Improvements for `colr` box.

[jozefchutka]

I noticed that currently the colr (Colour Information Box) is only parsed and exposed for hvc1SampleEntry (HEVC), but not for avc1SampleEntry (AVC/H.264) or other video sample entries.

To my knowledge the colr box is not specific to HEVC and can appear under any VisualSampleEntry (including avc1, avc3, and even vp09). It’s particularly relevant for AVC streams with HDR or non-BT.709 color spaces.

Suggested Implementation

Move colr parsing logic to VisualSampleEntry so all subclasses inherit it. This will also resolve the issue of hvc1SampleEntry not being exported and so there is no access to colr property in typescript.