cubicweb #2790319 "yes" predicate is no more importable from cubicweb.predicates [done]

This is an API regression.

Moreover we shouldn't require people to import from logilab.common.registry, which is just an implementation detail.

prioritynormal
typebug
done in3.16.2
load0.100
load left0.000
closed by#b638a99ab9cf [predicates] keep making `yes` predicate importable from cubicweb (closes #2790319)
patch[predicates] keep making yes predicate importable from cubicweb [applied]