feat: add fmp4 emsg ID3 support

[adrums86]

Description

Currently VHS does not support passing ID3 frames to the text track from fmp4 segment emsg boxes. With some additional parsing from mux.js and this PR, this enables passing parsed ID3 frame data to the player textTracks_ for use as timed metadata.

Specific Changes proposed

Adding a new function to the transmuxer-worker that calls getEmsgId3 on the transmuxer and returns parsed ID3 frames. Calling the worker function and passing the ID3 frames to the id3Fn passed in from the mediaSegmentRequest.

Note: This is blocked by the work in the transmuxer being released and integrated. See: videojs/mux.js#426
Changes are integrated into VHS see PR: #1372

References:
https://aomediacodec.github.io/id3-emsg/
https://dashif-documents.azurewebsites.net/Events/master/event.html#event-metadata-timing
https://github.com/id3/ID3v2.4/blob/master/id3v2.40-structure.txt

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors

[adrums86]

Setting as draft until transmuxer changes are integrated, as the tests will fail until we have access to the getEmsgId3 function.

[codecov]

Codecov Report

Merging #1370 (5847381) into main (e5b4bf6) will increase coverage by 0.04%.
The diff coverage is 90.90%.

@@            Coverage Diff             @@
##             main    #1370      +/-   ##
==========================================
+ Coverage   85.34%   85.39%   +0.04%     
==========================================
  Files          40       40              
  Lines        9957     9966       +9     
  Branches     2313     2314       +1     
==========================================
+ Hits         8498     8510      +12     
+ Misses       1459     1456       -3     

Impacted Files	Coverage Δ
src/transmuxer-worker.js	71.72% <66.66%> (+0.07%)	⬆️
src/media-segment-request.js	95.50% <100.00%> (+0.09%)	⬆️
src/source-updater.js	94.51% <0.00%> (+0.32%)	⬆️

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