Complete map overhaul.

-Added a 3D Skybox
-Sealed a hole in B site
-Optimization

Updates based on Feedback from the Source Engine discord Playtest session:
-The spawn system has been replaced with a "priority spawn" system,similar to the one seen on Vertigo
-Blocked the area between T-Mid and A completely
-Mid is now a little bit larger
-Added two sets of stairs near the B catwalk
-Added two crates on the B plant zone
-Made the window near B short a little bit smaller
-Moved the plastic crate on A site to give the Ts a safe plant
-Made Wallbangs a lot less effective around the map
-Added a window near the Garage connector
-A site has less elevation changes
-Added a small wall in A-connector
-Made the "CT underpass" area Safer to reach from CT spawn
-Reworked the "T Underpass" area
-Added new Tarp models around the map (Provided by 9yz#5386)
-Optimization stuff

Hotfix regarding a nodraw near B-Backsit

-Added a few door frames around the map
-Adjusted a displacement near CT-Mid
-Added a decal near A-Catwalk
-Swapped flickering light entities with Normal,Always active ones.
-Changed the Radar Colours
-Changed Factions for CT Side:
CTs Are now FBI

-Widened entrance to B
-Made it easier to throw a Molotov into the Catwalk Corner in A
-Added a crate in Mid
-Added a piece of wood to seal off a sightline from A-Short to B-Side hall
-Optimization

-Added custom signs
-Adjusted timings
-Fixed a spawn clip not working
-Removed Neon lighting outside Small office

-Moved the large crate on T-mid to provide more cover
-Changed floor material in Garage
-added cover near underpass
-Optimization
-Lighting fixes

Based on feedback:
-Added a New route to Bombsite A
-Added a connector between CT and mid
-added a connector between T-mid and B-main
-removed double doors
-added a large crate near T-mid
-added cover into both bombsites
-lighting improvements
-clipping improvements

-Light entities fixes