Fix error when cloning block with 0 columns in GroupingAggregatedTransform

Fix error Cannot clone block with columns because block has 0 columns ... While executing GroupingAggregatedTransform. It happened when setting distributed_aggregation_memory_efficient was enabled, and distributed query read aggregating data with different level from different shards (mixed single and two level aggregation). #10063 (Nikolai Kochetov).