ingesters/als_733_SAXS.py needs to handle list of files

[davramov]

Since we can't guarantee that the folder containing bl733 scan data only contains data from one scan, we need the ingester to accept a list of files to ingest into SciCat.

[davramov]

This also means updating the ingest function to handle either a single Path or list[Path].

See the related issue in splash_flows: als-computing/splash_flows#109