Bug 36227: Remove item group option if there are no items

Bug 36227: Remove item group option if there are no items

To test:
1. Test from OPAC. Any item group without items in it should not display as an option in the "Request specific item group:" dropdown

Signed-off-by: Caroline Cyr La Rose <caroline.cyr-la-rose@inlibro.com>
Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 3ed4e096b017a539a3b9afdb913f9d61fb43a0f5)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
(cherry picked from commit 81089c1f249d9b6febe1c884e1a8652b7fa864ce)
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>