lock/unlock pathways/containers with appropriate key

[Zaechus]

Will probably have to add a key object variant and an optional "password" field for pathways and containers that the key matches with.

Note that locked doors can be picked. This should probably be improved as well to require a certain type of object and the door should allow or disallow picking.

[Zaechus]

A Key Item variant has been added.

[Zaechus]

The Key Item now contains a "code" field and the Locked variant of the DoorLock enum contains a String for the same purpose