Replaced sw::Format with VkFormat

Replaced sw::Format with VkFormat

To avoid format conversion issues and simplify the code, sw::Format
was replaced with VkFormat. sw::Format only contained formats with
exact 1:1 correspondence with an equivalent VkFormat, with the
exception of YUV formats, which will require a minor adjustment in
SamplerCore::sampleTexel().

Bug b/119620767

Change-Id: I8124cbc40e1031a5b233156a10e87c35f1334eef
Reviewed-on: https://swiftshader-review.googlesource.com/c/22549
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>