Patron blocks: Allow for override of Borrowing when logged in user has credentials

Overview:
This is the first part of the patron block override, which is the case when the logged in user has the credentials to to the override. When is determined that borrowing, renewing or requesting will be blocked, the logged in user's credentials will be checked. If they have the patron block override credential, the Override button will appear in the patron block modal. If they do not, only the Close button and View block details button will appear (as they do now). In the future, instead of just displaying the Close button and View block details button, we will display a modal that allows for a supervisor patron block override code to be entered. This is user story UIU-1170.

Scenarios:

1. Scenario
   • Given patron has automated and/or manual patron blocks and logged in user has patron block override credential
   • When modal 'Patron blocked from borrowing' displays
   • Then add Override button to the left of the current Close button (as shown in attachment Borrowing-block.jpg)
2. Scenario
   • Given 'Patron blocked from borrowing' modal displaying with Override button active (Scenario 1 above)
   • When the Override button is clicked
   • Then open 'Override patron block' modal (as shown in attachment Patron-block-override-comment.jpg) with Save & close button inactive
3. Scenario
   • Given 'Override patron block' modal displaying with Save & close button inactive (Scenario 2 above)
   • When the Cancel button is clicked
   • Then close 'Override patron block' modal and go back to 'Patron blocked from borrowing' modal
4. Scenario
   • Given 'Override patron block' modal displaying with Save & close button inactive (Scenario 2 above)
   • When something entered in required Comment field
   • Then activate Save & close button
5. Scenario
   • Given 'Override patron block' modal displaying with Save & close button active (Scenario 4 above)
   • When the Save & close button is clicked
   • Then
     • Allow items to be scanned for checkout, requiring no further patron block overrides for the patrons during this checkout session
     • For each item checked out during this session, the Loan Action must be 'Checked out through override' and the Comment entered on the 'Override patron block' modal must appear in the Comments field, as shown in the attached Loan Details example FF-details-with-patron-block-override-on-borrowing.jpg
     • There may be item overrides required if an item is non-loanable for an item limit has been reached
     • The comment entered for an item override must be included in the Loan Details Comment field along with the patron block override Comment (in other words, there will be cases when two comments must be included in the one _Comment field)