Bug 35386: Add RESTAPIRenewalBranch system preference

Bug 35386: Add RESTAPIRenewalBranch system preference

This patch adds a new system prefernce, RESTAPIRenewalBranch, analogous to the existing OpacRenewalBranch system preference.

The preference allows choosing how the renewal branch is recorded in the statistics table.
In order ot preserve existing behaviour, the default is to use the api user's branch.

To test:
1 - Checkout some items to a patron
2 - Add an API user account with circulation permissions and a different homebranch
3 - POST a renewal to: http://localhost:8080/api/v1/checkouts/{checkout_id}/renewal
4 - Check statistics table and confirm the api users branch was used
5 - Apply patches, restart all
6 - Repeat API renewal, confirm same branch used
7 - Change the RESTAPIRenewal syspref
8 - Repeat API renewal and confirm specified branch is used
9 - Confirm the syspref works for all settings

Signed-off-by: Brendan Lawlor <blawlor@clamsnet.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>