Use dedicated hash table for new material names.
Updates a lot of dependent code:
- surface patches now target materials, not textures:
`s/_xvk_textures/_xvk_material`
- patching now affects only materials, not texture ids. All logic that
depends on texture ids now operate on original textures.
- brush normal smoothing now ignores patched surface materials when
deciding whether two surfaces can be smoothed.
The rationale is that patching should only affect newer PBR/RT code paths.
Legacy ref_interface_t texture access is not refcountable. It does
create/destroy texture in a single call regardless of other users.
Track it with a separate flag that affects refcount with a single +1/-1.
Too many places in the engine and the renderer expect texture names to
be insensitive: RAD files, material references, probably engine and game
calls too.
Make it universally case insensitive. Also, add rudimentary tests for
it.
Known issues:
- pbr materials are completely broken. They end up not being able to
find textures, seemingly due to memory corruption on materials side,
not textures.
- There are still places that try to get texture=1