Library spectrum USI column in SME table

[YasinEl]

Hello, and thank you for maintaining this tool!

We propose adding a “query_spectrum”, and “Library spectrum USI” column to the SME table. The “query_spectrum” should be populated as described in #223 with e.g. ms_run[x]:123 with 123 being the scan ID in the mzML file or spectral_representation[x]:123 when using a spectra collection as proposed in #222.

“Library spectrum USI” should be an USI to an annotated spectrum (e.g. a GNPS library spectrum such as mzspec:GNPS:GNPS-LIBRARY:accession:CCMSLIB00012558659)