Bug 34467: OAI GetRecord bad encoding for Unimarc

Bug 34467: OAI GetRecord bad encoding for Unimarc

For some Unimarc biblio records, the OAI Server returns a bad XML
document, ie a document with extended characters, such as accents, not
encoded in UTF8. It seems to come from somewhere in MARC::Record library
trying to deduce biblio record endoding from some fields. It may work
for MARC21 records. It doesn't for Unimarc records. So it's necessary to
send to the method transforming record into XML the marcflavour. This
way there is no encoding guessing from Unimarc biblio records content.

https://bugs.koha-community.org/show_bug.cgi?id=34467
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>