Lock Vehicle button shouldn't vanish when booking time period ends

[grundleborg]

At the moment the "lock" / "unlock" buttons in the bookings UI for customers only appear if booking_start_time < now() < booking_end_time. This means if you are late returning a vehicle you can't look it from within the web app.

The current logic is correct for the unlock button, however, it needs to be changed for the lock button to be the same as the logic checking whether you can lock a vehicle with a card tap works, which is essentially:

• If still within booking time, user can lock vehicle.
• If outside of reservation time, user can lock vehicle only if they have rights to the booking currently active on the box for that vehicle.

The hardware.box object stores the currently active booking as part of it's state. To avoid duplication of code, there is probably already a function somewhere that checks this case and handles it properly for card taps. If possible, we should use the same logic to check whether to show/accept the "ulock" action in the bookings UI so that it always stays consistent.

[grundleborg]

@Scilly-guy this seems like a good more challenging ticket to take on at some point, and would also be really useful for us operationally by reducing the number of bookings stuck in "late" state.