Added a test version of the hub area of the game called "The Sanctum"
Players can use this new area to select other levels if they wish.

- Added some new particles to Wardens
- Wardens now drop health pickups on death
- Updated explosion VFX
- Added some new visuals to the pause menu
- Added a new health pickup
- Added a small visual change to the loading screen
- Updated the Super Shotgun ammo pickup
- Fixed a bug with weapon switching on controller
- Fixed an issue with the skybox in E1M0
- Added some extra climbable surfaces to E1M0