Subdivision had its own store of shaders. Best to move them to
`draw_shader.cc` where all draw manager related shaders are stored.
Includes some small tweaks:
- Use enum class for shader types
- patch evaluation must now be retrieved via the
`DRW_shader_subdiv_get`. Previously there were 2 ways to retrieve
them, and one didn't support all the variations.
- Use strongly types when possible (`GPUVertCompType`).
Pull Request: https://projects.blender.org/blender/blender/pulls/134213
a475678701