Passing time for stationary generators and other immobile vehicles

[cake-pie]

Summary

Features "Passing time for stationary generators and other immobile vehicles"

Purpose of change

Resolves #63135

Describe the solution

Full range of checks for situations permitting / not permitting passing of time while in control of a vehicle

• Rail vehicle on rails: always allowed, control is optional. (Assumes no broken rails.)
• Aircraft in flight: never allowed, even if in stationary hover (which still consumes fuel, what if you run out?)
• Falling vehicle: no, it's moving!
• Moving vehicle: of course not
• Stationary vehicle (velocity == 0) with a nonzero target speed (cruise_velocity):
  • viable watercraft (enough flotation) floating in water: no, it will move
  • viable land vehicle (enough wheels) on ground or fording shallow water: nope
  • neither of the above: yes! \o/
• Non-viable watercraft (insufficient flotation) in deep water: no, it will sink
• Anything else (e.g. sitting at the controls of a stationary vehicle (velocity == 0) with no intention of accelerating (cruise_velocity == 0)): yes, but this was already possible before.

Describe alternatives you've considered

Just slapping a check for insufficient wheels and calling it done.

Testing

• debug spawn a children's tricycle
• install bicycle alternator and storage battery
• remove wheels
• use debug to drain half of the charge out of the battery
• hop on, take control and press up arrow a couple times to start pedaling
• observe that cruise speed > 0 while actual speed still 0
• press | to pass time while remaining at vehicle controls
• pick something like 30min to 1 hour, watch as time passes
• check that battery has been charged up

Additional context