This updates `fmt` to the latest version and moves to just being a copy
of their repo to make updating easier (no editing their cmake / figuring
out which files to minimally include).
The motivation for this is now that we switched to C++ 20, there were a
ton of deprecated function usages that is going away in future compiler
versions. This gets rid of all those warnings.
Effects the following files:
- [x] vehicle-rider
- [x] vehicle-control
- [x] vehicle-effects
- [x] vehicle
~~- [ ] vehicle-util~~
- [x] vehicle-physics
- [x] vehicle-states
~~- [ ] vehicle-guard~~
~~- [ ] traffic-engine~~
~~- [ ] traffic-manager~~
With the exception of traffic-engine, most of these files are either
done or have 1-3 stubborn functions remaining. Draft while I try to
resolve as many as possible / cleanup names and such.
Co-authored-by: water <awaterford111445@gmail.com>