BibIndex: fix new-old record incremental indexing

• Fixes incremental indexing leak for "new old" records, i.e. new records that were uploaded as if they were old, via some 005 value from the past. (closes #2693)

• Also, amends find_affected_records_for_index() default parameter values from mutable empty lists to immutable None in order to prevent potential mishaps.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>