Bug 11906: regression test for using DBIC to store & fetch UTF8 strings

Bug 11906: regression test for using DBIC to store & fetch UTF8 strings

This patch adds a regression test for verifying that a
DBIx::Class schema object initialized by Koha database sets up
the database connection to correct store and retrieve UTF8
values as Perl utf8 strings.

To test:

[1] Apply this patch.
[2] Run prove -v t/db_dependent/Koha_Database.t
[3] The test should fail.
[4] Apply the main patch for this bug, then do step 2 again.
[5] The test should pass.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit b21d16ca75bb40371773d3008fcb06c67200ab36)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>