Raycast using the Geometry class

[jarneson]

There's fully custom raycasting logic for selecting geometry: https://github.com/jarneson/godot-ply/blob/main/addons/ply/nodes/ply.gd#L141

We can just use Geometry from the engine.

Along the way this should make it easier to fix accidentally selecting things behind what we are trying to click

[fire]

Looking into it.

[fire]

From chat:

Convert code to ray casting to:

• vert -> sphere
• edge -> cylinder
• face -> tris