Add Office Rooms into the map

[moxvallix]

I have imported the office room assets into the main map. However, the walls and some z-ordering needs to be figured out still.

[github-actions[bot]]

HOW TO REVIEW:

• Test multiplayer (client and host)
• Check build status
• Check UI
• Check the code
• Check build artifacts

[nicemicro]

All changes shown here have been already merged.