chore: PR template and validation updates (#3582)

## Purpose of this PR
This PR aims to increase the quality of our PRs by enforcing certain
considerations and setting examples via PR template. This will also help
with Playtesting and validation of our changes by providing a better way
to evaluate PRs for potential playtest specification or release
blocking.
It is similar to an "official" suggestion from
https://github.com/orgs/community/discussions/84771

New PR template will be working as a "guide" on what would be nice to
have in it but the content in the template is more of an example. What
matters are sections:

1. **Documentation** --> Should describe what documentation
changes/corrections followed the code changes. This aims to help
catching any missing docs but if no documentation changes (API docs,
Documentation~) were needed then you can just acknowledge this fact in
this section
2. **Testing and QA** --> Should explain what testing coverage was added
for the code changes. This helps to understand if a given change will
require playtesting or is it fully covered by automated tests. This can
range from "a new sample was created with..." to "edge case issue that
is covered by added automated test". Note that **WE SHOULD ALMOST
ALWAYS** add some form of testing. The proposed content of this section
helps to see if you performed some manual testing (if you created some
project it's always worth linking but no need), it also helps with with
general evaluation of changes.
3. **Backport** --> A section that we already have. Should enforce
consideration if those changes should be ported to
`develop`/`develop-2.0.0` branches respectively
4. **Jira ticket** section was added for consideration if such PR is big
enough to require Jira ticket present. Note that this section is not
mandatory but may be flagged by QA when evaluating PRs for release. I
would assume that if PR takes more than a day of work then it should
have a corresponding Jira ticket

Those sections make it WAY easier to evaluate PRs that landed when we
want to release the package. It allows to see developer thinking on
important areas and works as a reminder for them so in case of looking
at the PRs it's easier for the QA to analyze those.
Important to note are :

- PR template was updated with more sections where **Documentation**,
**Testing and QA**, and **Backport** sections are **REQUIRED** for a PR
to be merged.
- I renamed the git workflow and I will update the name in the settings
when merging this PR so for now you can see backport-verification
pending since it doesn't exist anymore.
- **Testing and Documentation** section was basically divided into
separate **Documentation** and **Testing and QA sections**

Such updated PR template will look as follows
<img width="1388" height="1855" alt="image"
src="https://github.com/user-attachments/assets/7fe2f129-0440-48c3-98a3-b0eb9bae8e62"
/>

### Jira ticket
MTT-12822

### Documentation
No documentation changes or additions were necessary.

## Testing & QA
This change won't affect users and focuses around our workflow and
templates so no testing is needed

## Backport

#3583

Author: michalChrobot

.github/pull_request_template.md

@@ -1,36 +1,61 @@
-<!-- Replace this block with what this PR does and why. Describe what you'd like reviewers to know, how you applied the engineering principles, and any interesting tradeoffs made. Delete bullet points below that don't apply, and update the changelog section as appropriate. -->
+## Purpose of this PR
+[//]: # (
+Replace this block with what this PR does and why. Describe what you'd like reviewers to know, how you applied the engineering principles, and any interesting tradeoffs made. 
+)
 
-<!-- Add short version of the JIRA ticket to the PR title (e.g. "feat: new shiny feature [MTT-123]") -->
+### Jira ticket
+_Link to related jira ticket ([Use the smart commits](https://support.atlassian.com/bitbucket-cloud/docs/use-smart-commits/))_
 
-## Changelog
+### Changelog
+[//]: # (updated with all public facing changes  - API changes, UI/UX changes, behaviour changes, bug fixes. Remove if not relevant.)
 
 - Added: The package whose Changelog should be added to should be in the header. Delete the changelog section entirely if it's not needed.
-- Fixed: If you update multiple packages, create a new section with a new header for the other package. 
-- Removed/Deprecated/Changed: Each bullet should be prefixed with Added, Fixed, Removed, Deprecated, or Changed to indicate where the entry should go.
-
-## Testing and Documentation
-
-- No tests have been added.
-- Includes unit tests.
-- Includes integration tests.
-- No documentation changes or additions were necessary.
-- Includes documentation for previously-undocumented public API entry points.
-- Includes edits to existing public API documentation.
+- Fixed: If you update multiple packages, create a new section with a new header for the other package.
+- Removed/Deprecated/Changed: Each bullet should be prefixed with Added, Fixed, Removed, Deprecated, or Changed to indicate where the entry should go
 
 <!--  Uncomment and mark items off with a * if this PR deprecates any API:
 ### Deprecated API
 - [ ] An `[Obsolete]` attribute was added along with a `(RemovedAfter yyyy-mm-dd)` entry.
-- [ ] An [api updater] was added.
+- [ ] An [api updater](https://confluence.unity3d.com/display/DEV/Obsolete+API+updaters) was added.
 - [ ] Deprecation of the API is explained in the CHANGELOG.
 - [ ] The users can understand why this API was removed and what they should use instead.
 -->
 
-## Backport
+## Documentation
+[//]: # (
+This section is REQUIRED and should mention what documentation changes were following the changes in this PR. 
+We should always evaluate if the changes in this PR require any documentation changes.
+)
 
-<!-- If this is a backport:
- - Add the following to the PR title: "\[Backport\] ..." .
- - Link to the original PR.
-If this needs a backport - state this here
-If a backport is not needed please provide the reason why.
-If the "Backports" section is not present it will lead to a CI test failure. 
--->
+- No documentation changes or additions were necessary.
+- Includes documentation for previously-undocumented public API entry points.
+- Includes edits to existing public API documentation.
+
+## Testing & QA
+[//]: #  (
+This section is REQUIRED and should describe how the changes were tested and how should they be tested when Playtesting for the release.
+It can range from "edge case covered by unit tests" to "manual testing required and new sample was added".
+Expectation is that PR creator does some manual testing and provides a summary of it here.)
+
+### Functional Testing
+[//]: # (If checked, List manual tests that have been performed.)
+_Manual testing :_
+- [ ] `Manual testing done`
+
+_Automated tests:_
+- [ ] `Covered by existing automated tests`
+- [ ] `Covered by new automated tests`
+
+_Does the change require QA team to:_
+
+- [ ] `Review automated tests`?
+- [ ] `Execute manual tests`?
+
+If any boxes above are checked, please add QA as a PR reviewer.
+
+## Backport
+[//]: # (
+This section is REQUIRED and should link to the PR that targets other NGO version which is either develop or develop-2.0.0 branch
+Add the following to the PR title: "\[Backport\] ..."
+If this is not needed, for example feature specific to NGOv2.X, then just mention this fact.
+)

.github/workflows/backport-verification.yml

@@ -0,0 +1,62 @@
+# This workflow is designed to verify that the pull request description contains a required sections that are important from quality perspective.
+# ## Backport section is important as a reminder to account for backports for anyone that works with NGO repository (to 1.X or 2.X branches respectively).
+# ## Testing & QA section is important to ensure that the PR has appropriate testing coverage and is important when QA will evaluate PRs before Playtesting for the release.
+# ## Documentation section is important to ensure that the documentation is updated with the changes made in the PR.
+
+# If any of the sections is missing, the workflow will fail and block the PR from merging, prompting the developer to add those sections to the PR description.
+# The workflow is configured to run when PR is created as well as when it is edited which also counts simple description edits.
+
+name: "NGO - PR Verification"
+
+on:
+  pull_request:
+    types: [opened, edited, synchronize, reopened]
+    branches:
+      - "develop"
+      - "develop-2.0.0"
+      - "/release\/.*/"
+
+jobs:
+  pr-verification:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Check PR description
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const pr = context.payload.pull_request;
+            const body = pr.body || '';
+
+            // List of mandatory PR sections
+            const requiredSections = [
+              {
+                header: '## Backport',
+                description: 'PR description must include a "## Backport" section. Please add this section and provide information about this PR backport to develop or develop-2.0.0 branch respectively or explain why backport is not needed.'
+              },
+              {
+                header: '## Testing & QA',
+                description: 'PR description must include a "## Testing & QA" section. Please add this section and provide information about the testing performed for this PR. It can range from adding unit tests to full samples and is needed from QA side to analyze PRs while Playtesting for the release.'
+              },
+              {
+                header: '## Documentation',
+                description: 'PR description must include a "## Documentation" section. Please add this section and provide information about the documentation changes made in this PR. It is important to keep the documentation up to date with the code changes.'
+              }
+            ];
+
+            const missing = requiredSections.filter(section => !body.includes(section.header));
+
+            if (missing.length > 0) {
+              let message = 'PR description is missing the following required section(s):\n';
+
+              const missingDescriptions = missing.map(
+                s => `- ${s.header}: ${s.description}`
+              );
+
+              message += missingDescriptions.join('\n');
+              message += '\n\nPlease add them to your PR description.';
+
+              core.setFailed(message);
+            }