Laser Quiz 3000 v0.4 update

• First off, I didn't really feel comfortable with the association of guns and a school classroom, so I removed explicit guns and you can now only 3D-print the Laser Banana. Honestly it does the same job. It even has a laser sight. But it's not a gun, and that's important.
• Second off, I renamed the game from The Guns of Eratosthenes to Laser Quiz 3000.
• Performance has been significantly improved from about 45 FPS to the 72 FPS required for Quest. I did this mostly by a few "standard tricks", I'll put a list at the end. This was most of the work from v0.3 to v0.4.
• Rearranged the whole room, high score table is now a big screen to the right, challenge tags have been spread out, and most of the interactable items are on the left of the room just because that's where the focus of the game is. Also it's better lit.
• The 3D Printer wasn't really meant to be the focus of the original game but it's great fun and popular with my small group of play-testers, so I made a few changes there - you can now 3D-print some different things and I'll build on that in future.
• The letter boards were previously untextured and it was hard to tell when your sticky letter was close to the board. By adding textures it is now much easier and more natural as the human brain can now figure out the distance from the stereo VR image.

Gameplay changes

• In the maths quizzes, the operators (+, -, x) are now a different colour so that e.g. 2--2 is less confusing!
• There's an indication of where to stand for the quiz
• You can cancel the options screen (where you're choosing a level)
• You can cancel the Exit process if you shoot the trash can by mistake
• There's a printable CAB and it has a small interaction on it :-)
• The game says hello to you, indicating that your player name has been registered for the high scores
• After a game, the high score table you just tried out for is highlighted in yellow
• Renamed "Geography" to "Capital Cities"
• Added a blackboard with more instructions

Some of the technical changes

• Switched from real-time to baked illumination (big frame rate boost)
• Combined most of the static meshes into a few big meshes (small frame rate boost)
• Switched off shadows etc. on the remaining non-static objects
• Removed colliders and other overhead on scenery outside the classroom
• Converted the volumetric letters from pooled to static objects so we can pre-bake their lighting
• Extended and debugged the "game state machine" to correctly transition between states like "Quitting" and "Roaming".