Pushable/Pullable/Dragables

[kevingranade]

Add option to drag an item that is too heavy to lift.
Drug items will occupy one or more hands, and slow the player down based on weight of the item. Also may cause additional noise and impose movement limitations.

Draggable containers would accept objects dropped on them, and provide a bonus to being dragged (reducing the effective weight for the purposes of being dragged) based on the type of item..

Pushable containers would act like draggable ones, but have an override to make the pushable container lead instead of following when moving. e.g. shopping cart.

[kevingranade]

Implementation notes:
Implement as a vehicle, vehicle interaction menu to grab/release conditional on the vehicle being light enough to drag.
Grabbing status would be a player variable pointing at the vehicle. the coordinates of the grab.
Possibly allow a grab to be established on e.g. furniture as well.
Grabbing an item would be problematic, since an item has to be disambiguated somehow.
Grabbing furniture or an item would need a dedicated command.

[kevingranade]

At long last this is implemented! By #2520
Any additional issues with it can be covered by new issues.