Moves FileSet association to Work to the end of the ingest process (Bulkrax only).

[bwatson78]

• app/actors/hyrax/actors/file_set_actor.rb: moves this callback to just after the FileSet/Work association point.
• app/jobs/associate_filesets_with_work_job.rb: creates a separate job that associates all of the FileSets going into a work at once.
• app/jobs/attach_files_to_work_job.rb: since we're processing the FileSet/Work association here instead of inside file_set_actor, this moves the callback to right after that association.
• config/initializers/bulkrax.rb:
  • removes the index/number of files details as arguments since we're now doing the FileSet/Work association that needed that information to its own Job.
  • overrides the Bulkrax::ScheduleRelationshipsJob so that we can insert a call to the new AssociateFilesetsWithWorkJob at the end of the ingest process.
• lib/importing_modules/file_set_methods.rb: deletes the FileSet/Work association process and the looping information needed for it to run from this point in the ingestion process.