Vehicle bay elevator stuff

[SabreML]

About the pull request

Makes the Vehicle Bay elevator work better.
Specifically:

• Adds some ASRS sound effects, and tweaks the timing of various elements to line up with them.
• Adds the pre-existing vehicle bay elevator shaft sprite for when the elevator has been lowered. (No animation yet though)
• Adds \proper to /turf/open/floor/almayer/empty and the elevator shaft effect to change the grammar of its examine text:
  Before/After:
  
• Fixes(?) the front guard rails not raising when the elevator is lowered.
• Fixes a bug where the shipside docking port would fall into the elevator shaft after the elevator left:
  
• Fixes an oversight where a human falling into the vehicle bay elevator shaft would be teleported to the requisitions elevator.
• Fixes the gear things at the corners of the elevator spinning constantly until it's called back up.

(See comparison videos below)

Explain why it's good for the game

The vehicle bay elevator doesn't get used often, but it does get used. This will hopefully make it feel a bit less janky.

Testing Photographs and Procedure

Screenshots & Videos

Sending the elevator down and up again:

(Unmute for sound on both videos)

Before:

before.mp4

After:

after.mp4

(I've also tested this with #5401, and it seems to work without any issues.)

Changelog

🆑
add: Made the vehicle bay elevator look and sound better when in use.
fix: Fixed the vehicle bay elevator's front railings not closing when the elevator was lowered.
fix: Fixed the vehicle bay elevator's docking port falling down the elevator shaft when it was lowered.
fix: Fixed falling into the vehicle bay elevator shaft teleporting players to the requisitions elevator.
/:cl:

[Drulikar]

Everything here appears to be working; though I think we should also fix a couple other aspects while we're at it:

/obj/structure/machinery/door_control/railings/use_button early returns on if(!is_mainship_level(SSshuttle.vehicle_elevator.z)) even if the railing is down (desiredstate is 1). We should always allow railing to go up.

SSshuttle.vehicle_elevator.timeLeft() should be changed to shuttle.has_arrive_time() so its isn't just always "Moving" (looking for the actual reference to the shuttle atm) I'd just instead test against whether the SSshuttle.vehicle_elevator.mode != SHUTTLE_IDLE.

This should achieve all that: