cubicweb-container #2708809 hooks: set_container_relation must compute who is the parent [resolved]

else the subsequent operation fails, having a permuted pair of entity/parent ...

priorityimportant
typebug
done in1.0.1
load0.100
load left0.000
closed by#818fe576762b [hooks] the set_container_relation hook must also give eids in entity/parent_of_entity order to its operation (closes #2708809)
patchhooks: the set_container_relation hook must also give eids in entity/parent_of_entity order to its operation (closes #2708809) [applied]