Fixed format validations

Fixed format validations

Format validations were failing if the exact same format
wasn't used between different texture related calls to the
same texture, even when the formats were equivalent, so I
added a GetSizedInternalFormat function based on a format
map (courtesy of Angle). The validation checks were also
unified in utilities.cpp and used wherever texture formats
were used, to make sure Image objects used in Texture
objects always use the sized format, so that format
comparisons work properly.

Change-Id: I72fc8fb1b0f135ac679c274866e5b8e223541e7f
Reviewed-on: https://swiftshader-review.googlesource.com/4082
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>