Added enums for mostly implemented format, along
with the implementation for 2 new formats:
VK_FORMAT_B4G4R4A4_UNORM_PACK16
VK_FORMAT_A2B10G10R10_UINT_PACK32 (as a true integer format)

Bug b/119620767

Change-Id: I139408609cdbc35f7d9b0a8220e86a598c70a9e9
Reviewed-on: https://swiftshader-review.googlesource.com/c/23309Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Corentin Wallez <cwallez@google.com>