Bug 21649: Pass guarantee info to template when adding child

Bug 21649: Pass guarantee info to template when adding child

To test:
1 - Find an adult patron
2 - Click 'Add child'
3 - Note address/phone info does not carry over
4 - Apply patch
5 - Repeat
6 - Note information populates

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Todd <tgoatley@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
It works, but the code is ugly and hard to maintain.

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>