Bug 15173: Restore SubfieldsToAllowForRestrictedEditing

Bug 15173: Restore SubfieldsToAllowForRestrictedEditing

Bug 7673 introduced SubfieldsToAllowForRestrictedEditing but bug 12176
broke it assuming that only selects were impacted by this feature.

Test plan:
Go back on bug 7673 and confirm that
SubfieldsToAllowForRestrictedEditing is working as expected with this
patch applied.

Signed-off-by: Lee Jamison <ldjamison@marywood.edu>
For clarification, the item fields that are entered in
SubfieldsToAllowForRestrictedEditing should EXCLUDE the desired
fields you want to disable.

Test plan (updated to test the scenario in the bug Description):
1. Create a patron with only the following permissions:
    - catalogue (Required for staff login)
    - editcatalogue -> edit_catalogue
    - editcatalogue -> edit_items
    - editcatalogue -> edit_items_restricted
2. Navigate to Administration -> Global system preferences -> Cataloging
    -> Record Structure -> SubfieldsToAllowForRestrictedEditing
3. In the input field for SubfieldsToAllowForRestrictedEditing enter in
    all the 952 fields EXCEPT the ones desired to be disabled. In this
    case, we want to disallow editing of 952$2, 952$a, 952$b, 952$e, 952$h,
    and 952$o so we enter the following into the
    SubfieldsToAllowForRestrictedEditing (without quotes) "952$0 952$1
    952$3 952$4 952$5 952$7 952$8 952$c 952$d 952$f 952$g 952$i 952$j
    952$p 952$t 952$u 952$v 952$w 952$x 952$y 952$z"
4. Click Save all Cataloging preferences
5. Login to the staff client as the created restricted editing patron
6. Edit an item
7. Note that all fields except for the ones excluded from the syspref
    are editable

Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>