Fixing grouped expressions for arrays of hashes with keys > 1


Changing `.filter(...).andGroupedOr([{a:1, b:2}, {c:3, d:4}])` 
to `... AND (a=1 AND b=2) OR (c=3 AND d=4)`
instead of `... AND (a=1 OR b=2 OR c=3 OR d=4)`