Last tranche of new SkColorTypes

This CL adds:
    kAlpha_F16_SkColorType
    kRG_F16_SkColorType
    kRGBA_16161616_SkColorType,

which should be it for a while.

Bug: skia:9121
Change-Id: I81b9d46a202a76e9b7d7ca86495d72dbdae32576
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/241357
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Reed <reed@google.com>
28 files changed