Bug 27813: Restore default order on suggestion list view

Bug 27813: Restore default order on suggestion list view

Prior to 20.05, suggestions on /cgi-bin/koha/suggestion/suggestion.pl sorted by
suggesteddate by default. On 20.05 and later, they're sorting by title instead.
We should go back to the previous behavior.

Test plan:
Create some suggestions
Edit the suggestions.suggesteddate in the DB
List the suggestions and confirm that there are sorted by oldest first

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>