Support h.264 codec in re_video

[jprochazk]

rerun/crates/store/re_video/src/mp4.rs

Lines 31 to 42 in 07291e5

	// TODO(jan): support h.264, h.265, vp8, vp9
	let stsd = &video_track.trak(&mp4).mdia.minf.stbl.stsd;
	let codec_name = if stsd.avc1.is_some() {
	"avc"
	} else if stsd.hev1.is_some() {
	"hevc"
	} else if stsd.vp09.is_some() {
	"vp9"
	} else {
	"unknown"
	};
	return Err(VideoLoadError::UnsupportedCodec(codec_name.into()));

[jprochazk]

We can load h264 as of #7470, but playback is choppy. Remaining work here is to fix how we pass timestamps to the video decoder, which requires some restructuring of our buffering logic.