Implement "Awaiting Pickup" Item status

Purpose:
To implement a status of "Awaiting Pickup" for requested items that are being held for pickup by the requester

Scenarios:

1. Scenario
   • Given a checked out item X with:
     • One or more active requests (currently indicated by item status "Checked out - Recalled" or "Checked out - Held")
     • Request Fulfillment preference for the request at the top of the request queue* = Hold shelf
   • When item X is checked in
   • Then Item X’s status should change to “Awaiting pickup”
2. Scenario
   • Given item X with status of “Awaiting pickup”
   • When checked out to the requester
   • Then item X's status should change to:
     • "Checked out" if there are no active requests on the item
     • "Checked out - Recalled" if there is an active recall request on the item and it is at the top of the request queue*
     • Checked out – Held”: If there is an active hold request on the item and it is at the top of the request queue*
3. Scenario
   • Given item X with status of “Awaiting pickup”
   • When checked out to a user who is NOT the requester for the request at the top of the queue*
   • Then a message should appear "This item is awaiting pickup by a different user"
   • No check out will occur

*NOTE: The "request queue" is the list of active requests for an item. Request queue management hasn’t yet been implemented so let's just assume that the oldest active request is at the top of the queue (first in first out)

NOTE: Scenario 2 may actually already be working