Fix approx_percentile_cont_with_weight update_batch bug

[Ted-Jiang]

https://github.com/apache/arrow-datafusion/blob/5d70c32a9a4accf21e9f27ff5ed62666cbbcbe54/datafusion/physical-expr/src/aggregate/approx_percentile_cont_with_weight.rs#L137-L155

each call self.approx_percentile_cont_accumulator.merge_digests(&digests); in update_batch will lose accumulator own inner status by

https://github.com/apache/arrow-datafusion/blob/118eecdc8384805cae752dac0c4ccc768cc9629b/datafusion/physical-expr/src/aggregate/approx_percentile_cont.rs#L286-L289