Break out record_attrs ingest into separate function

Break out record_attrs ingest into separate function

Haven't tested revised biblio.indexing_ingest_or_delete yet but can
confirm that "SELECT id, biblio.ingest_marc_attrs(2356712, marc) FROM
biblio.record_entry WHERE id = 2356712;" works.

Rationale was that we somehow had a case where metabib.record_attrs was
empty for a record and there wasn't a good way to populate it without
busting this out into a separate function.

Signed-off-by: Dan Scott <dscott@laurentian.ca>