Improve element gallery header

[bmarty]

Content

Improve element gallery header.

Now that we have many supported languages, the header is not rendering nicely, see how https://element-hq.github.io/element-x-android is rendering now:

This PR groups the language into a dropbox, as per below:

Also this PR add a click to copy URL to ease sharing element from the gallery per URL.

Node: code change with the help of Gemini.

Motivation and context

Give a little bit of love to Element Gallery

Screenshots / GIFs

See above

Tests

• Open ./screenshots/index.html and see the change on the header
• Click on an image and observe that the url is copied
• Click on an image name (header) and observe that the url is copied

Hopefully the effect will be more visible on the next full element gallery generation

Tested devices

• Firefox

Checklist

• Changes have been tested on an Android device or Android emulator with API 24
• 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
• You've made a self review of your PR

[github-actions]

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[sonarqubecloud]

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

[ganfra]

LGTM I guess!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.42%. Comparing base (82ef2e0) to head (501d066).
⚠️ Report is 2 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #6239   +/-   ##
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  Coverage    81.42%   81.42%           
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  Files         2570     2570           
  Lines        69798    69798           
  Branches      8950     8950           
========================================
  Hits         56833    56833           
  Misses        9645     9645           
  Partials      3320     3320           

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