Bug 31122: Terminology - Replace occurences of 'Notices & slips' with 'Notices and...

Bug 31122: Terminology - Replace occurences of 'Notices & slips' with 'Notices and slips'

Replace occurences of 'Notices & slips' with 'Notices and slips'
(replacing '&' and '&amp' with 'and'), as per the terminology
guidelines.

See the terminology list:
https://wiki.koha-community.org/wiki/Terminology

Test plan:
1. Find occurrences of 'Notices & slips':
   - git grep 'Notices & slips' -- :^misc/translator/po
   - git grep 'Notices & slips'
2. Review places in the staff interface where 'Messages & slips' is
   displayed:
   - Tools home page
   - Tools > Notices & slips: page title and breadcrumb
   - Other breadcrumbs:
     . Tools > Notices & slips > New notice > [select any module]
     . Tools > Notices & slips > [select Edit for any notice]
     . Tools > Notices & slips > [select Delete for any notice]
3. Review other occurences:
   . The cron job description for misc/cronjobs/holds/holds_reminder.pl:
     misc/cronjobs/holds/holds_reminder.pl -man (scroll down to the
     description)
   . The TalkingTech README file:
     vi misc/cronjobs/thirdparty/TalkingTech.README
4. Apply the patch.
5. Re-run the grep queries from step 1 - no occurences are now found.
6. Review places where 'Notices & slips' was found in steps 2 and 3 -
   these should all be replaced with 'Notices and slips' and should
   read correctly.
7. Sign off!

Alernative: review the diff for the patch and check that occurences of
'&amp' and '&' are replaced with 'and' and the updated text reads
correctly.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>