Add full SVG support

[bxdxnn]

Content

Support SVG throughout the app (avatars, timeline, media, etc.)

Needs matrix-org/matrix-rust-sdk#6662

1. Revert Send SVG images as files #4595
   2. Wire Coil's SvgDecoder to media loader
2. Fallback to full content fetching in case a thumbnail doesn't exist
3. Fetch a bit more metadata from the SVG when sending it (thumbnail still won't be set because SVGs are commonly light in size like normal messages)

Motivation and context

There was poor to no support before.

Screenshots / GIFs

Tests

• Send SVG (needs fix(ffi): Fix attachment upload failing when blurhash isn't present matrix-org/matrix-rust-sdk#6662)
• See SVG

Tested devices

• Physical
• Emulator
• OS version(s): 16

Checklist

• I am aware of the etiquette.
• This PR was made with the help of AI:
  • Yes. In this case, please request a review by Copilot.
  • No.
• 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 (related: Draft: Remove white background from stickers/images #6068)
• 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 defines 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]

Thank you for your contribution! Here are a few things to check in the PR to ensure it's reviewed as quickly as possible:

• If your pull request adds a feature or modifies the UI, this should have an equivalent pull request in the Element X iOS repo unless it only affects an Android-only behaviour or is behind a disabled feature flag, since we need parity in both clients to consider a feature done. It will also need to be approved by our product and design teams before being merged, so it's usually a good idea to discuss the changes in a Github issue first and then start working on them once the approach has been validated.
• Your branch should be based on origin/develop, at least when it was created.
• The title of the PR will be used for release notes, so it needs to describe the change visible to the user.
• The test pass locally running ./gradlew test.
• The code quality check suite pass locally running ./gradlew runQualityChecks.
• If you modified anything related to the UI, including previews, you'll have to run the Record screenshots GH action in your forked repo: that will generate compatible new screenshots. However, given Github Actions limitations, it will prevent the CI from running temporarily, until you upload a new commit after that one. To do so, just pull the latest changes and push an empty commit.

[bmarty]

Thanks, a few remarks.

[bmarty]

Thanks for the update. 2 more remarks then I think that we're good to merge this change.

[bmarty]

Thanks!

[codecov]

Codecov Report

❌ Patch coverage is 54.23729% with 27 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.62%. Comparing base (a3a0fda) to head (4fd0be1).
⚠️ Report is 252 commits behind head on develop.

Files with missing lines	Patch %	Lines
...ibraries/mediaupload/impl/SvgDimensionExtractor.kt	48.38%	9 Missing and 7 partials ⚠️
...roid/libraries/matrix/ui/media/CoilMediaFetcher.kt	0.00%	6 Missing ⚠️
...oid/libraries/matrix/impl/media/RustMediaLoader.kt	0.00%	2 Missing ⚠️
.../libraries/matrix/api/exception/ClientException.kt	0.00%	1 Missing ⚠️
.../libraries/matrix/ui/media/ImageLoaderFactories.kt	0.00%	1 Missing ⚠️
...aries/mediaupload/impl/AndroidMediaPreProcessor.kt	94.44%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #7020      +/-   ##
===========================================
- Coverage    80.64%   80.62%   -0.02%     
===========================================
  Files         2678     2679       +1     
  Lines        76229    76283      +54     
  Branches     10252    10265      +13     
===========================================
+ Hits         61474    61503      +29     
- Misses       10824    10842      +18     
- Partials      3931     3938       +7     

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