Metadata processing: Add file ID, characterization

refs #6575

Metadata files should have identification and characterization information in the METS file. Add those microservices to metadata processing. Update processing config to reflect this. Fix a couple microservice group discontinuities.
I didn't add a 'choose file ID' microservice - I'm using the same one for metadata as for submission docs, since %IDCommand% is still around. Just updating the text on the processing config to make this clear.