Bug 20229: Explicitly list the SQL modes we support

Bug 20229: Explicitly list the SQL modes we support

In our installation procedure we ask the administrator to edit the
MySQL|MariaDB configuration file to specify the SQL modes we support
(see bug 17258 comment 6 and 7 for more information).

We are on the way to catch and fix all these issues and support these
stricter modes (as they highlight problem in our codebase/DB structure)
but in the meanwhile it may be good to remove this step and revert the
changes when we are ready.

TODO:
- Remove that for dev installations (to let developers catch these bugs)
- Edit the wiki page to remove this step

Test plan:
0. Do not apply this patch
1. Edit your MySQL|MariaDB config and add:
sql-mode = "ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
to the [mysqld] section (or edit it)
2. Restart your DBMS
3. Try to make the app explode (watch the logs)
(tips: you should get "'koha_kohadev.me.id' isn't in GROUP BY" when
editing an order)
4. Apply the patch, restart_all, restart your DBMS
5. Try to recreate the failure
=> You should no longer see the error in the logs

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>