Fix long click not working for media timeline items

[jmartinesp]

Content

Add nullable onContentClick and onLongClick callbacks for the media timeline item content, so they can register custom actions for these user interactions.

Motivation and context

#3864 introduced a regression that prevented long click from working on media and location items unless they had a caption.

Screenshots / GIFs

No screenshot changes, I hope.

Tests

On a room, long press on:

• An image/video item.
• An image/video item with captions.
• A sticker.
• A location item.

You can double check other items too, but these should be the ones that changed.

Tested devices

• Physical
• Emulator
• OS version(s): 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 title will be used in the release note, it clearly define what will change for the user
• 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

[github-actions]

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[codecov]

Codecov Report

Attention: Patch coverage is 61.90476% with 8 lines in your changes missing coverage. Please review.

Project coverage is 82.90%. Comparing base (7222a1f) to head (1aa937b).
Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
...imeline/components/TimelineItemGroupedEventsRow.kt	0.00%	4 Missing ⚠️
...ssages/impl/timeline/components/TimelineItemRow.kt	50.00%	0 Missing and 1 partial ⚠️
...e/components/event/TimelineItemEventContentView.kt	66.66%	1 Missing ⚠️
...meline/components/event/TimelineItemStickerView.kt	0.00%	0 Missing and 1 partial ⚠️
...timeline/components/event/TimelineItemVideoView.kt	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3879      +/-   ##
===========================================
- Coverage    82.90%   82.90%   -0.01%     
===========================================
  Files         1785     1785              
  Lines        45105    45111       +6     
  Branches      5326     5328       +2     
===========================================
+ Hits         37396    37398       +2     
- Misses        5843     5844       +1     
- Partials      1866     1869       +3     

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[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud