cubicweb #4891552 [dataimport] make NoHookObjectStore compatible with datafeed source [validation pending]

currently, it's not able to create entities which are seen as coming from an external source with a proper extid.

prioritynormal
typeenhancement
done in3.20.6
load1.000
load left0.000
closed by#080ac14df6fa [dataimport] make MetaDataGenerator / NoHookObjectStore usable from a datafeed parser
patch[dataimport] make MetaDataGenerator / NoHookObjectStore usable from a datafeed parser [applied][dataimport] don't generate metadata which are explicitly specified [applied][dataimport] make MetaDataGenerator / NoHookObjectStore usable from a datafeed parser [applied][dataimport] don't generate metadata which are explicitly specified [applied]