Adjust module for December release and change too many things at once

* apply Black formatting
* use plural for sub-commands, for consistency
* fix convert_to_recid() to always fetch the first PID of type 'recid'
* add command to reindex all (or some) records
* update method for instantiating RecordServices: allow the configuration
  of a factory function that creates a RecordService as desired
  (default: fetches services from current_rdm_records)