video_core: Implement S8_UINT format

gl_texture_cache: Implement pixel format conversions for copies

Prevent window flickering when holding Esc

It should be noted that on Windows, only nvidia gpus support this format natively as of this commit.

ci: Don't fetch submodules when fetching PRs

hotkeys: Don't allow hotkeys to spam

Reported on discord by Levlight. Don't try to exit fullscreen if it's already off.

This allows the usage of the FormatConversionPass to be applied to more than the previously used BGR conversion scenarios.

Project A.R.T. Advanced Rendering Techniques

CMakeLists: Update catch to 2.13.7

Keeps the testing libraries up to date.

Texture Cahe/Shader decompiler: Resize PointSize on rescaling, refactor and make reaper more agressive on 4Gb GPUs.

Fixes Bayonetta 2 on AMD