Make WebCodecs isConfigSupported more accurate by relying on codec creation code path
<rdar://problem/101278486>
Pull request: https://github.com/WebKit/WebKit/pull/5481
Committed 255717@main (2231e02d1348): <https://commits.webkit.org/255717@main> Reviewed commits have been landed. Closing PR #5481 and removing active labels.
Re-opened since this is blocked by bug 246741
Pull request: https://github.com/WebKit/WebKit/pull/5535
Committed 255775@main (2c09844aebd2): <https://commits.webkit.org/255775@main> Reviewed commits have been landed. Closing PR #5535 and removing active labels.