Bug 31890: Add surname to PrefillGuaranteeField system pref

Bug 31890: Add surname to PrefillGuaranteeField system pref

To test:
1. Apply patch and restart_all
2. Find the system preference PrefillGuaranteeField
3. Look for the Surname option and add it
4. Go to a patron account and add a gaurantee
5. See that the surname is properly populated for the gaurantor's surname field

Note:
This patch replaces borrower_data.surname with patron.surname. There seems to be a mismatch here so I filed Bug 32458.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>