Add fields `datatype` and `assay` to datacards

[cmatKhan]

datatype has levels 'binding' or 'perturbation_response'

assay has levels: 'callingcards', 'chec-seq', 'chip-chip', 'chip-exo', 'chec-seq'

perturbation_mechanism: 'tfko', 'overexpression', 'degron',

platform: 'array' or 'sequencing' (this is only for expression)

This then needs to be added to the virtualDB config file. We'll need to figure out how this works with binding, which doesn't have platform.

[cmatKhan]

This is done via virtual_Db config in tags now