[WIP] vehicle menu tweak

Guys, that's my first experience in cpp, so all comments are really welcomed. Also, I can't compile current windows build due to some json errors, so I would ask @Cata-Jenkins to compile it before release. The main idea is to tweak code of vehicle menu, and [partially] fix the issue #3031 (even pre-defined names of some cars like military cargo Truck looks bad now).