Use official API to override backend templates

[froemken]

Remove ext_typoscript_setup.typoscript

It overrides module templates the old way.
It contains TypoScript like plugin which is not available at that point

Remove ext_typoscript_constants.typoscript

It only contains the module template paths for ext_typoscript_setup.typoscript. As that file was removed, there is no need to keep it.

Restructure backend module template

Having backend templates in 3 different folders is bad design:

• Resources/Private/Templates/Backend
• Resources/Private/Layouts/Backend
• Resources/Private/Partials/Backend

Much better is one folder for backend module usage:

• Resources/Private/Backend/Templates/
• Resources/Private/Backend/Layouts/
• Resources/Private/Backend/Partials/

That's also the format, which the new override mechanism prefers (PageTS Config). That's why we use page.tsconfig here. It can NOT be part of a Site Set, as BE modules work page tree independent (yes, there are exceptions).

Before Merge

There are some links/includes referencing files of this extension. Before merge please make sure, that all links are still working.

[linawolf]

I will take care of the includes in the aftermath

[linawolf]

@froemken should this be backported to 12.4?

[froemken]

Feature: #96812 - Override backend templates with TSconfig comes in with TYPO3 12. So, yes, we should backport it to TYPO3 12.

[github-actions]

The backport to 12.4 failed:

The process '/usr/bin/git' failed with exit code 1

stderr

error: could not apply 01462f0... Use official API to override backend templates
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".
hint: Disable this message with "git config set advice.mergeConflict false"

stdout

Auto-merging Configuration/page.tsconfig
CONFLICT (add/add): Merge conflict in Configuration/page.tsconfig

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-12.4 12.4
# Navigate to the new working tree
cd .worktrees/backport-12.4
# Create a new branch
git switch --create backport-162-to-12.4
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 01462f07fe60482ee7faa684e38eb4e9450facf5
# Push it to GitHub
git push --set-upstream origin backport-162-to-12.4
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-12.4

Then, create a pull request where the base branch is 12.4 and the compare/head branch is backport-162-to-12.4.