Trigger material update on texture update

[GiantBlargg]

This PR makes textures store which materials they were used in, and when the texture changes, triggers material updates for all stored materials. This fixes some issues where a material would continue using an out of date texture.

Fixes #52505

[clayjohn]

Makes sense to me!

Needs @reduz' approval before merging.

[BastiaanOlij]

Makes sense to me too

[reduz]

To be entirely honest, I wanted to deprecate proxy textures. They add a lot of complexity and they are not as efficient in Vulkan as they were in OpenGL. Their main use case was 2D animated textures for tilemaps, but this was now solved better in a different way.

[GiantBlargg]

@reduz

Proxy textures are still used by AnimatedTexture and ViewportTexture. Could these be modified to work without a proxy texture?

Even if proxy textures were removed there are still instances when a texture is replaced (e.g. render targets and procedural textures) that would still need a version of this PR.

[akien-mga]

Superseded by #54489.