* Only two texture import modes for low/high quality now:
* S3TC/BPTC
* ETC2/ASTC
* Makes sense given this is the general preferred and most compatible combination in most platforms.
* Removed lossy_quality from VRAM texture compression options. It was unused everywhere.
* Added a new "high_quality" option to texture import. When enabled, it uses BPTC/ASTC (BC7/ASTC4x4) instead of S3TC/ETC2 (DXT1-5/ETC2,ETCA).
* Changed MacOS export settings so required texture formats depend on the architecture selected.
This solves the following problems:
* Makes it simpler to import textures as high quality, without having to worry about the specific format used.
* As the editor can now run on platforms such as web, Mac OS with Apple Silicion and Android, it should no longer be assumed that S3TC/BPTC is available by default for it.
