Bug 22073: Add to diacritics mappings for Ž and ž

Bug 22073: Add to diacritics mappings for Ž and ž

To test:
1 - Find or add a record by author Slavoj Žižek
2 - Search for 'Zizek'
3 - No results
4 - Apply patch
5 - Reindex
6 - Search again
7 - Success!

https://bugs.koha-community.org/show_bug.cgi?id=22073

Signed-off-by: Eric Phetteplace <ephetteplace@cca.edu>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
(cherry picked from commit 5c313bc554a857da29f124957d58459c0ed4c03b)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>