Making Color use a single ColorSpace enum instead of two enums

Currently Color has two different enums that can be used to know the
color space of the color, and also the serialization type of it.

To avoid confusion and make it more compact, we are merging these two
enums to a single colorSpace enum.
Eventually, that can be used also to represent the
colorInterpolationSpace.

Low-Coverage-Reason: This code is being tested in fast tests.
Bug: 1092638
Change-Id: I1cc340e563183c6301b1cd615f5a86bb9cd5a81d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3937629
Commit-Queue: Juanmi Huertas <juanmihd@chromium.org>
Reviewed-by: Aaron Krajeski <aaronhk@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1062823}