Show review decision and reviewers in PR card

[wx-03]

Summary:

Fixes #408
Fixes #443

Type of change:

• ✨ New Feature/ Enhancement

Changes Made:

• Added a logo in the PR card to show the review decision (changes requested / review required / approved)
• GitHub avatars of reviewers are shown in the PR card, with tooltips that show the username and review state (changes requested / approved / commented / dismissed / pending)
• Added an icon to indicate when PRs have been merged without any review
• Tests have not been added in this PR and should be done under the PR for issue Create unit tests for issue model #453.

Screenshots:

When the icons and avatars are unable to fit into the same line as the labels and milestone, they will be wrapped to the next line:

Proposed Commit Message:

Show review decision and reviewers in PR card

Review decisions and reviewers are not shown in PR card.

Showing review decions and reviewers will allow users to see what needs
to be done and which PRs require reviews at a glance, and showing 
reviewers allows tutors to gauge the level of PR reviews in the team.
Displaying an icon for PRs that have been merged without reviews can 
help tutors to easily identify PRs that violate best practices for 
software engineering.

Let's ,
* display review decions in the PR card,
* display the GitHub avatars of PR reviewers in the PR card,
* use tooltips to show information about reviews, and
* display an icon for PRs that have been merged without any review.

Checklist:

• I have tested my changes thoroughly.
• I have created tests for any new code files created in this PR or provided a link to a issue/PR that addresses this.
• I have added or modified code comments to improve code readability where necessary.
• I have updated the project's documentation as necessary.

[damithc]

@wx-03 shall we show all these stuff in the same line (but overflow to next line if cannot fit in one line), to optimise vertical space usage?

[wx-03]

@wx-03 shall we show all these stuff in the same line (but overflow to next line if cannot fit in one line), to optimise vertical space usage?

I have updated it to show the review decision icon on the right side of the reviewers, and it will now be on the same line as the labels and milestone, unless there is not enough space.

[Eclipse-Dominator]

The functionality looks great!

For minor improvements, some small refactoring can be done, otherwise its lgtm

---

I also noticed some unusual errors that seem to be coming from GitHub's side:

It’s unclear if this requires additional logic to address since its a respond from the graphql servers (I think), so we can leave this as a potential future issue for now.

[wx-03]

The functionality looks great!

For minor improvements, some small refactoring can be done, otherwise its lgtm

I also noticed some unusual errors that seem to be coming from GitHub's side:

It’s unclear if this requires additional logic to address since its a respond from the graphql servers (I think), so we can leave this as a potential future issue for now.

@Eclipse-Dominator Thanks for the review, I have made the necessary changes.

[Eclipse-Dominator]

LGTM for me.
Let's see what others think about the design changes.