Remove support for sample weight from exact COUNT aggregation
Migrate HLL aggregations to new base class
Migrate approximate count distinct to new aggregation base class
Add method to define a default noop constructor
Fix intellij warning
Refactor new aggregation base classes to reduce code duplication
Remove BlockCursor from approximate COUNT(*)
Remove support for sampled data from percentile aggregations
Remove BlockCursor from CustomSum aggregation
Merge SimpleAggregationFunction and AbstractAggregationFunction