mesa: fix CopyTexImage format compatibility checks for ES
What does this MR do and why?
mesa: fix CopyTexImage format compatibility checks for ES
the ES spec imposes additional requirements for copy commands,
specifically that the formats have matching component sizes
the existing check used the driver's internal formats to check
for a match, which is broken since the spec requires the match be
between the passed internalFormat and the buffer's effective internal
format (i.e., this has no relation to what the driver supports)
fixes KHR-GLES3.copy_tex_image_conversions.forbidden* on a bunch of drivers
cc: mesa-stable