Video: Rename `PIXEL_FORMAT_P{0|2|4}16` to `PIXEL_FORMAT_P{0|2|4}10`

The idea of using `PIXEL_FORMAT_P{0|2|4}16` for all 10/12/16 bit videos is
obviously unscientific, although there should be no physical data store
difference with these hbd formats, but the meanings are different.

This is causing some actual issues, e.g:

1. We don't actually know if `PIXEL_FORMAT_P016LE` means 16 bit or 12bit
or 10bit. so we always return 16 from `VideoFrame::BitDepth()`, this makes
the color space transform function has to use hardcode 10bit as workaround
to solve it.

2. We always expect a 1-to-1 mapping of PIXEL_FORMAT vs GMB and
MultiPlaneFormat, so this is going to cause issue, if in the future we
want to expand the support to 12bit or 16bit.

Bug: 347597908
Change-Id: I0c6f55398151ed7e60edafb0dd6d03c30f1e62ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5633141
Reviewed-by: Johannes Kron <kron@chromium.org>
Commit-Queue: Sida Zhu <zhusida@bytedance.com>
Reviewed-by: Dan Sanders <sandersd@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1316697}