Convert Correlation to UDAF #10884

Is your feature request related to a problem or challenge?

Similar to other issues in #8708 Move datafusion/physical-expr/src/aggregate/correlation.rs to datafusion/functions-aggregate/src/correlation.rs

I found CovarianceAccumulator in datafusion/physical-expr/src/aggregate/covariance.rs is not removed, we should remove it and use the one in datafusion/functions-aggregate/src/covariance.rs instead. The same with StddevAccumulator

Describe the solution you'd like

No response

Describe alternatives you've considered

No response

Additional context

No response