Vehicles should follow basic land geometry

[platote]

Is your feature request related to a problem? Please describe. I'm a bit frustrated with the vehicle system: it seems that vehicles can only move on a flat plane, not following the geometry beneath it.

Describe the solution you'd like Vehicles should at least follow the geometry i.e falling when there is none for instance

Describe alternatives you've considered My knowledge on vehicles is based on : https://webaverse.notion.site/Creating-Vehicles-d579c3099d9b4af48e9037b1a33b6d44, and the hovercraft repo, so maybe there are other ways to do vehicles

https://user-images.githubusercontent.com/84842352/182622383-21e66657-55c3-4a9b-b451-d471606439f8.mp4

[jakezira]

Related: https://github.com/webaverse/app/issues/1541

[jakezira]

Clear assign due to low priority.