CSG tooling is unintuitive and a bit tedious to use

[jayrulez]

Proposing that the CSG tooling is refactored to make the tool more useful and intuitive.

I think the Whitebox tooling in O3DE, the GreyBoxing tooling in ezEngine, or the procedural geometry tooling in LumixEngine are good references (UX) if the CSG tooling here is to be refactored.

[DW01]

For reference, here's how it currently appears to work:

1. Create an Entity and add both a SolidComponent and GroupComponent. This holds the actual CSG primitives.
2. Right click that Entity and click Add entity.
3. Click on the subentity you've just created and add a PrimitiveComponent.
4. Set it to whatever Shape you want and pray that the Default Shader loads properly (if it doesn't, find it under System/Shape/Shaders in the database and open it, then go back to the Scene viewport).
5. Configure Extent and Position for the PrimitiveComponent and its parent Entity.
6. Repeat 2-6 for as many CSG primitives as you want to add, and configure them how you see fit.

Yeah. This is a bit awkward and tedious compared to more modern approaches. It should also be noted that PrimitiveComponents added this way don't seem to cast shadows regardless of whether Casts Shadows is checked on a light pointed at them or not, but they do receive lighting.