Bugfix: make TravelingVendor.Save MT friendly
- get rid of wheel flags processing, they were updated on server and sent over, but not used
- cache linear velocity every fixed step (we're missing on interpolation, but we only send the snapshot every fixed update anyway)
- use manually interpolated steeringAngle instead of querying the wheel collider
Tests: TestMTSave(down to 5 remaining), ran TravelingVendorTest scene and looked at the vendor as it drove around