rsx: Texture cache fixes and improvments

gl/vk/rsx: Refactoring; unify texture cache code
gl: Fixups
- Removes rsx::gl::texture class and leave gl::texture intact
- Simplify texture create and upload mechanisms
- Re-enable texture uploads with the new texture cache mechanism
rsx: texture cache - check if bit region fits into dst texture before attempting to copy
gl/vk: Cleanup
- Set initial texture layout to DST_OPTIMAL since it has no data in it anyway at the start
- Move structs outside of classes to avoid clutter

rpcs3/Emu/RSX/Common/TextureUtils.cpp

@@ -393,7 +393,7 @@ u8 get_format_block_size_in_bytes(rsx::surface_color_format format)
 	}
 }
 
-static size_t get_placed_texture_storage_size(u16 width, u16 height, u32 depth, u8 format, u16 mipmap, bool cubemap, size_t row_pitch_alignement, size_t mipmap_alignment)
+size_t get_placed_texture_storage_size(u16 width, u16 height, u32 depth, u8 format, u16 mipmap, bool cubemap, size_t row_pitch_alignement, size_t mipmap_alignment)
 {
 	size_t w = width;
 	size_t h = std::max<u16>(height, 1);