replace shader state matrix by texture

[Novakasa]

this might help with current block rendering issues, where I'm guessing the float to int precision doesn't hold up for high values, making some of the states go bad.

Replacing the matrix by an explicit texture of ints will probably help

[Novakasa]

int textures in godot seem to have issues, this might be a workaround though: godotengine/godot#57841 (comment)