opengles Translator: get Compressed texture handling out from GLEScontext

This commit does few things:
1. Gets doCompressedTexImage2D out of the context and TextureUtils
2. Gets palette textures out of TextureUtils and into PaletteTexture
3. Makes TextureUtils generic for all compressed textures
4. Moves the glGet's dealing with compressed textures from GLEScontext to the impl.

Change-Id: Ibbde6968810a66a4f3488f3887ee3f015fc32c11
10 files changed