cubicweb #2054468 support for HAVING in SET/DELETE queries [validation pending]

INSERT would be cool but that's another story (as current behaviour isn't expected in some cases, making it hard to upgrade yet)

prioritynormal
typeenhancement
done in3.14.0
load0.200
load left0.000
closed by#f01c80513274 [rql] closes #2054468: support for HAVING in SET/DELETE queries