Airlock - Add offline cleanup process

[eladiw]

Description

As a TRE Developer
I want to create an offline process which deletes abandoned airlock requests
So that their storage will be freed

Acceptance criteria

• define (configration) stale limit
• create a new offline process which cleans up the storage for these requests
• Optional - move state to a new state (abandoned)?

[tanya-borisova]

Need to decide:

• where is the process initiated
• what are the statuses

From the UX perspective, we could also provide notifications: "You haven't touched a request for X days" (not part of this task).
Revoking a request would mean an online cleanup and is not part of this task.