GH-36 CLUT Support

[phy1um]

Additions

• Setting CLUT fields with TEX2 register in sprite rendering (only takes effect for PSM8/PSM4 textures)
• Lua abstraction for arbitrary buffers (used to create dynamic textures in EE RAM)
• Better TGA loading, no longer needs to specify width and height manually
• Python tooling for working with TGA images
  • Extract palettes into own image
  • Strip palette from TGA
  • Compress TGA into 4 bit per pixel non-standard image (for PSM4)
• Correct VRAM size calculations to be in bytes always (but FBs still expect words?)

Todo Before Merge

• [ ] Verify on hardware
• [ ] Update tests to use new APIs