hls: support generating streams with multiple audio tracks (#2728)

[aler9]

Fixes #2728

This allows to generate HLS playlists and streams with multiple audio tracks. The embedded HLS player was improved with a button, displayed in the top right corner of the screen, that allows to change the audio track.

This has been tested with Chrome and Firefox. There are still compatibility issues with iOS.

Nightly binaries

https://github.com/bluenviron/mediamtx/actions/runs/10980959304

[dams92210]

Works great after few tests. Thank you!

[codecov]

Codecov Report

Attention: Patch coverage is 24.29907% with 81 lines in your changes missing coverage. Please review.

Project coverage is 56.03%. Comparing base (8960cba) to head (ff372bc).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/protocols/hls/from_stream.go	20.40%	78 Missing ⚠️
internal/servers/hls/muxer_instance.go	66.66%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3793      +/-   ##
==========================================
- Coverage   56.09%   56.03%   -0.06%     
==========================================
  Files         194      194              
  Lines       19304    19320      +16     
==========================================
- Hits        10828    10826       -2     
- Misses       7638     7657      +19     
+ Partials      838      837       -1     

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[github-actions]

This issue is mentioned in release v1.9.2 🚀
Check out the entire changelog by clicking here