cubicweb-brainomics #3314076 Remove identifier ? [validation pending]

There are too much identifiers attributes that are not useful. They should be removed for most of the subject's specific entity types (assessment, questionnaire run, ...)

prioritynormal
typebug
done in0.9.0
load0.500
load left0.000
closed by#19125fe8a1c0 [test/schema, views, importers] Backport identifier attributes removal on suject-specific entities (closes #3314076)
patch[test/schema, views, importers] Backport identifier attributes removal on suject-specific entities (closes #3314076) [applied]