fix(server/vehicle): send vehicle properties on db creation

[andreutu]

This PR aims to add the vehicle properties to the vehicle's metadata, which will get added to the database, on creation.

[andreutu]

Did a small change. Basically, when creating a vehicle, the properties are under data.properties. But, when spawning one, the properties are under data.data.properties. The recent commit should check both cases of where the data can exist.
I think (and hope) that these changes are good enough and don't require any more tinkering.