Bug 36169: Patron categories with type='Staff' should be able to have guarantees

Bug 36169: Patron categories with type='Staff' should be able to have guarantees

Library staff - whose patron category has a type='Staff' should be able to have guarantees added.

Test plan:
1) Create a 'Library staff' patron category with 'Category type' = 'Staff'

2) Create a patron account using the 'Library staff' patron category

3) Notice the '+ Add guarantee' button is not displayed in the members toolbar for the 'Library staff' patron you created

4) Apply patches and restart services

5) Refresh your browser window

6) Notice the '+ Add guarantee' button is now displaying for the 'Library staff' patron

7) Confirm you can successfully add a guarantee

8) Run unit test t/db_dependent/Koha/Patrons.t

Sponsored-By: Waitaki District Council, New Zealand
Signed-off-by: Tadeusz „tadzik” Sośnierz <tadeusz@sosnierz.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>