Bug 14759: Replace Text::Unaccent with Unicode::Normalize

Bug 14759: Replace Text::Unaccent with Unicode::Normalize

As shown in the comments on the bug, it appears that Unicode::Normalize
is the most reliable way to strip accents from strings for this use
case.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Joy Nelson <joy@bywatersolutions.com>
(cherry picked from commit 27de0d61792d46e4fbf8bd8dba2d1d6f0a48c091)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>