Bug 35744: Implement +strings for GET /patrons/:patron_id

Bug 35744: Implement +strings for GET /patrons/:patron_id

In order to retrieve the library's name and patron category's
description alongwith other patron's info.

Test plan:
Run the following command before and after this patch:

% curl -u koha:koha --request GET 'http://localhost:8081/api/v1/patrons/42' --header "Content-Type: application/json" --header "x-koha-embed: +strings" | jq

Notice that you now have _strings which contains the library's name and
patron category's description

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>