Bug 33270: Add record_strip_nonxml routine to Koha::Biblio::Metadata

Bug 33270: Add record_strip_nonxml routine to Koha::Biblio::Metadata

This adds a routine that can strip non xml characters form a record.
It is intended for cases where we do not wish to throw an exception,
but rather need to process a record to allow other work to continue

To test:
prove -v t/db_dependent/Koha/Biblio/Metadata.t

Signed-off-by: Sam Lau <samalau@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>