Implement MSC4027 (Custom images in reactions)

[surakin]

Fixes #2159

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

Implement rendering of custom images in reaction per MSC4027

Motivation and context

Ran into mxc reactions while testing Element X and wanted to make it work

Screenshots / GIFs

Tests

• Send custom reaction using Cinny
• Observe the reaction showing up in Element X

Tested devices

• Physical
• Emulator
• OS version(s):
  Android 6, 13, 14

Checklist

• Changes have been tested on an Android device or Android emulator with API 23
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR

[jmartinesp]

It's working quite well, thanks! There are a couple of issues that should be fixed before it's merged, though.

[codecov]

Codecov Report

Attention: 14 lines in your changes are missing coverage. Please review.

Comparison is base (c2a7b38) 66.97% compared to head (5cf4dc8) 66.95%.

Files	Patch %	Lines
...impl/timeline/components/MessagesReactionButton.kt	58.82%	6 Missing and 1 partial ⚠️
.../components/reactionsummary/ReactionSummaryView.kt	53.33%	6 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2160      +/-   ##
===========================================
- Coverage    66.97%   66.95%   -0.03%     
===========================================
  Files         1375     1375              
  Lines        34219    34236      +17     
  Branches      7544     7546       +2     
===========================================
+ Hits         22919    22922       +3     
- Misses        7663     7675      +12     
- Partials      3637     3639       +2     

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[jmartinesp]

Thanks for the changes, LGTM! You might need to add an empty commit at the end so the CI runs again (stupid GH limitations for PRs coming from forks & CI-generated commits, sigh).

[bmarty]

Thanks for the PR @surakin !
Can I ask you to add a comment on this PR with screenshot with the 2 rendering using the latest code:

• timeline message with mxc reaction
• bottom sheet of the details of this image.

Thanks!

[surakin]

Custom reaction

Bottom sheet