cubicweb #1720823 [entity fetch_attrs] fetch ambiguous relations without fetch_attrs recursion [resolved]

To correct this bug we do no more fetch related entities that are the target of an ambiguous relation. We can fetch them however if we do not fetch their attributes (which would raise the pointed bug). This is much easier to implement now that this ticket is implemented.

done in3.14.0
load left0.000
closed by#8930f7a284dd [entity fetchattrs] also fetch ambiguous rtypes even if we do not recurse on them (closes #1720823)