uniqCombined() uses hashtable for medium cardinality, and since
HashTable resize by the power of 2 (well actually HashTableGrower grows
double by the power of 2, hence HashTableGrower::increaseSize() should
be overwritten to change this), with 1<<13 (default for uniqCombined)
and UInt64 HashValueType, the HashTable will takes:
getBufferSizeInBytes() == 131072
While it should be not greater then sizeof(HLL) ~= 98K, so reduce the
maximum cardinality for hashtable to 1<<12 with UInt64 HashValueType and
to 1<13 with UInt32, overwrite HashTableGrower::increaseSize() and cover
this using max_memory_usage.
Refs: https://github.com/ClickHouse/ClickHouse/pull/7221#issuecomment-539672742
v2: cover uniqCombined() with non-default K
