Create proper 3D models

[Fidge123]

• [x] Engine 3D model
• [x] Weapon 3D model
• [x] Repair 3D model
• [ ] Materials

[Fidge123]

first version of engine looks like this

[Fidge123]

this is how the game would look with these models --> screens taken on iOS

(The camera works but its really difficult to break it in a way that it would allow for good screenshots that show off the new models)

[Fidge123]

each wagon should be a lot longer than they are now :heavy_check_mark:

[Fidge123]

ref #175