Demo Update

Changelog:
- Improved Stone Model 2 collider to not break the collection system
- Tree in collider tower area was adjusted on the map
- Stone Model 2 now hides its renderer when broken
- Notification system no longer deactivates an already deactivated view
- Spawn Points adjusted to respect NavMeshAgents positioning
- Wave Manager prevents waves of 1 entity or no entity from appearing
- Hegnos no longer slows down after delivering some resources to the tower
- Enhancement tree fixed for some Hegnos enhancements
- Some sound effect tweaks