Bug 38177: Do not use stash to retrieve parameters

Bug 38177: Do not use stash to retrieve parameters

The pagination for EBSCO's titles, packages and resources is broken. We
shouldn't rely on $c->stash but use params from the request instead.

Test plan:
1) Setup all the system preferences in ERM:
<staff_url>/cgi-bin/koha/admin/preferences.pl?tab=erm
2) Enable EBSCO in ERMProviders. Set the ERMProviderEbscoApiKey and ERMProviderEbscoCustomerID prefs.
3) Do a search that returns more than 20 records. Click on a page other than 1. Notice the records do not change (Page is the same).
4) Apply patch. Repeat. Notice pagination now works.

Search titles, packages and resources
Use the pagination and modify the number of results per page

Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>