All instances of track ID are using either int or uint ; except for MediaSample that is using AtomString forcing to have back and forth conversion whenever we are checking or searching for a track.
<rdar://problem/106884653>
Pull request: https://github.com/WebKit/WebKit/pull/20901
Committed 271419@main (b3ffcc0a9df7): <https://commits.webkit.org/271419@main> Reviewed commits have been landed. Closing PR #20901 and removing active labels.