Add proximity based update manager

- An easier way to optimize frequently-updated objects
- Requires these to work
  - `Vector3 Position`
  - `float Proximity`
  - `void ProximityEnter()`
  - `void ProximityExit()`
  - `void ProximityUpdate()`
  - `void ProximityLateUpdate()`
  - `void ProximityFixedUpdate()` 