Correct various texture formats in OpenGL

This, along with the PNG fix, generally passes this test (so far):
https://github.com/DHrpcs3/rpcs3/commit/d745a7bb4ebd974523506655de5b2071cbf47932#commitcomment-6359180

It corrects mainly byteswapping and swizzling, but also a couple of the missing texture formats.  Did not really test any formats not present in that test, though.

-[Unknown]