Support skewness(x) in Aggregation function

[Weijun-H]

Is your feature request related to a problem or challenge?

Returns the skewness value calculated from values of a group.

Describe the solution you'd like

D SELECT skewness(col) FROM VALUES (-10), (-20), (100), (1000), (1000) AS tab(col);
┌────────────────────┐
│   skewness(col)    │
│       double       │
├────────────────────┤
│ 0.5745116147533554 │
└────────────────────┘

Describe alternatives you've considered

No response

Additional context

https://docs.databricks.com/en/sql/language-manual/functions/skewness.html
https://duckdb.org/docs/sql/functions/aggregates#skewnessx

[dharanad]

take

[dharanad]

Referring : https://github.com/duckdb/duckdb/blob/main/src/core_functions/aggregate/distributive/skew.cpp

[alamb]

Given #12357 we may want to move this function to some other repo rather than the core

[dharanad]

thanks for the update @alamb