Bug 24509: Fix API relared tests failing on MySQL8

Bug 24509: Fix API relared tests failing on MySQL8

This patch makes a trivial change to the tests so they catch the way
MySQL 8 reports the duplicate key message. The difference on the API
error message is irrelevant and so it is ok to just make the tests try
both MySQL 8 output and the rest of the supported engines.

To test:
1. Run:
   $ kshell
  k$ prove t/db_dependent/api/v1/acquisitions_orders.t \
           t/db_dependent/api/v1/libraries.t \
           t/db_dependent/api/v1/patrons.t
=> FAIL: Tests fail due to warning and conflict message differences
2. Apply this patch
3. Repeat 1
=> SUCCESS: Tests pass!
4. Sign off :-D

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>