Allow multiple texture and physics layer reference types

[Nicolas-Ferre]

Problem
Collision layers and textures are currently in 1 dimension (usize type).
But in the future, multiple modules could define their own textures (e.g. modor_graphics for texts) or collision layers (e.g. modor_ui for click or hover events).
It means there will be conflicts between modules.

Feature
Add resource layers to avoid conflicts between modules.

Examples
API to define.

Additional context

• See if a global solution can be implemented, or if it is necessary to handle it per resource type.