Bug 24666: Display not registered guarantors on the patron detail page

Bug 24666: Display not registered guarantors on the patron detail page

There was no way to see the not registered guarantors apart of editing
the patron.

Test plan:
- Create a patron with category type "Child"
- Define a "guarantor surname" and/or "guarantor firstname" in the
"Contact" block (the patron is not registered)
- See the patron's detail page and notice that the info appear
- Edit and add a registered guarantor
- See the patron's detail page and notice that the 2 guarantors info appear

Note that the relationship has been added.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>