Requests: add status filter

Purpose: Add a filter for the status Open - Not on shelf 

User story statement(s):

As a circulation librarian,
I want to filter different Requests based on status

Scenarios:

1. Scenario:
   • Given the Request app
   • When I view the Request status accordion in the Search & filter pane
   • Then Open - Not on shelf appears after Open - Not yet filled
     • Closed - Cancelled
     • Closed - Filled
     • Closed - Pickup expired
     • Closed - Unfilled
     • Open - Awaiting delivery
     • Open - Awaiting pickup
     • Open - In transit
     • Open - Not yet filled
     • Open - Not on shelf
2. Scenario:
   • Given the Open - Not on shelf status filter
   • When I click on it
   • Then requests with the status of Open - Not on shelf appear in the results in the Request status column