cubicweb #3252270 bad sql generated with some case of subquery [validation pending]

eg if a subquery variable is used in NOT EXISTS(X relation Y), then table for relation is added to wrong scope.

prioritynormal
typebug
done in3.17.11
load0.250
load left0.000
closed by#a5ce068143ad [rql2sql] fix relation table scope when some variable from subquery is used. Closes #3252270
patch[rql2sql] fix relation table scope when some variable from subquery is used. Closes #3252270 [applied]