Check the necessity documents verification for subsoil spec v2
Change subsoil document upload validation according to documentation
subsoil-english award documents:
https://gitlab.prozorro.sale/public-projects/documentations/-/blob/master/technical_specification/subsoil/subsoil-english/subsoil-english.md#%D0%B0%D0%B2%D0%B0%D1%80%D0%B4
AR: no validation error; ant type of docs could be uploaded
ER: validation error returns
spec v2, have methods for validate document allowed list for award and bid.
is that necessary in spec_v2 relative to spec_v1.
code_path: prozorro_sale.procedure.packages.subsoil.states.ActiveQualification