Describe the bug or unexpected behaviour
PR #4277 states that there is a memory leak in uniqState.

At least it was in version
ClickHouse: v19.1.6

How to reproduce

for i in {1..1000}; do clickhouse-client --max_memory_usage 100000000 <<< "SELECT uniqExactState(number) FROM system.numbers GROUP BY number % 1000"; done

Expected behavior
Memory usage should be bounded.

Additional context
We should check if bug is still present and fix it.