Patron blocks: Allow for override when logged in user does not have credentials

This user story will need to be rewritten as part of UXPROD-2645: Permission escalation for override

Overview:
This is the second part of the item block override. The first part (UIU-1781) is the case when the logged in user has the credentials to to the override. When is determined that checking out the item will be blocked, the logged in user's credentials are checked. If they have the item block override credential, the Override button will appear in the item block modal. If they do not, only the Close button will appear. In this user story (UIU-1288) we will change that to display a modal that allows for a supervisor item block override code to be entered.

Scenarios:

1. Scenario
   • Given patron has reached item block limit and logged in user does NOT have permission User: Can override item blocks
   • When modal 'Item not checked out' displays
   • Then display modal with Override code box and Override with code button to the left of Close button (as shown in attachment New-item-block-modal2.jpg)
2. Scenario
   • Given 'Item not checked out' modal (Scenario 1 above)
   • When Close button is clicked
   • Then:
     • Close 'Item not checked out' modal
     • Do not check item out to patron
3. Scenario
   • Given 'Item not checked out' modal (Scenario 1 above)
   • When the Override with code button is clicked with no value entered in Override code
   • Then:
     • Display error: Override code is required (as shown in attachment New-item-block-modal2-error1.jpg)
     • Do not check item out to patron
4. Scenario
   • Given 'Item not checked out' modal (Scenario 1 above)
   • When the Override with code button is clicked with invalid value entered in Override code
   • Then:
     • Display error: Invalid code entered--please try again (as shown in attachment New-item-block-modal2-error2.jpg)
     • Do not check item out to patron
5. Scenario
   • Given 'Item not checked out' modal (Scenario 1 above)
   • When the Override with code button is clicked with valid value entered in Override code
   • Then:
     • Close 'Item not checked out' modal
     • Check out item to patron
     • Display (Item limit overridden) under Loan Policy on Scanned items page (as shown in attachment New-scanned-items-list.jpg)