The `Math_INF` and `Math_NAN` defines were just aliases for those
constants, so we might as well use them directly.
Some portions of the code were already using `INFINITY` directly.
- Fixed SoftBody surface update with new rendering system
- Added GodotPhysics implementation for SoftBody
- Added support to get SoftBody rid to interact with the physics server
- Added support to get SoftBody bounds from the physics server
- Removed support for unused get_vertex_position and get_point_offset
from the physics server
- Removed SoftBody properties that are unused in both Bullet and
GodotPhysics (angular and volume stiffness, pose matching)
- Added RenderingServerHandler interface to PhysicsServer3D so the physics servers don't need to reference the class from SoftBody node directly
