Displacement map prototype (#26709)

Displacement map prototype (#26709)

Requires https://github.com/space-wizards/RobustToolbox/pull/5023

This uses the new engine features (above) to add a displacement map shader. This allows deforming a sprite based on another sprite.

Primary use case is automatically adapting human clothing sprites to different species, something we want to make species like Vox a reality.

A basic example of wiring this up with Vox has been added. The system is however incredibly simple and **will** need more work by a content developer to select and toggle displacement maps when appropriate. I am leaving that to somebody else. For example right now the displacement map is applied even if a species already has custom-fit sprites for a piece of clothing, such as the grey jumpsuit for Vox.

Basic Aseprite plugins to help with authoring displacement maps have also been made.