[ATLASDQ-853] Update metadata sensing to be a flag.
Moves the sensing of in-file-metadata to be its own flag, usable elsewhere too.
Also stops this throwing in the case that len(flags.Input.Files) == 0
, i.e. P1 mon.
Moves the sensing of in-file-metadata to be its own flag, usable elsewhere too.
Also stops this throwing in the case that len(flags.Input.Files) == 0
, i.e. P1 mon.