Feature/improvement - Release owner leash rights if owner is absent

[dracnoc]

What version of OpenCollar are you using?

8.2.3

What behavior did you expect?

The leash cannot be taken by others trust/group if an owner is absent and has left the wearer in a leashed state.

What behavior did you see instead?

Nobody else with collar/leash access can take the leash. Menu shows "Leashed to:" - no name is present.

What steps does someone need to take to reproduce the problem?

Attempt to take the leash after an owner has abandoned the leash (leashed but then the owner TP'd elsewhere).

Notes: The collar has Group access, but the overriding state of the Owner defeats this if the leash is abandoned. A periodic check would see who it is "Leashed To"