Bug 14779: Cannot paginate reviews

Bug 14779: Cannot paginate reviews

When having more than 20 (or numSearchResults) reviews waiting to be approved in <site>/cgi-bin/koha/reviews/reviewswaiting.pl?status=1,
the paging at the bottom only offset by 1 entry, instead of moving a full page (20 entries) ahead.

The simple fix uses 'page' instead of 'offset'.

TEST:
1) Modify numSearchResult preference to a low (5?) value.
2) create X comments, where X is greater than the value above.
3) approve them all (although this step is probably unnecessary)
4) Go to tools >> comments (approved comments tab)
5) You see X entries.  Click on page 2 at bottom.  Link should show "offset=2")
6) You get same results, except the first one which "slided out".

Apply patch, redo step 4-5.

With patch, paging works as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>