Implement GroupsAccumulator for corr(x,y) aggregate function

[2010YOUY01]

Which issue does this PR close?

Closes #13549

Rationale for this change

Implement GroupsAccumulator for corr aggregation function, for better performance when group cardinality is high

I rerun the H2o benchmark:

Data Generation

falsa groupby --path-prefix=/Users/yongting/data/ --size MEDIUM --data-format PARQUET
https://github.com/mrpowers-io/falsa

Run benchmark in datafusion-cli

CREATE EXTERNAL TABLE IF NOT EXISTS h2o_100m (
    id1 VARCHAR NOT NULL,
    id2 VARCHAR NOT NULL,
    id3 VARCHAR NOT NULL,
    id4 INTEGER NOT NULL,
    id5 INTEGER NOT NULL,
    id6 INTEGER NOT NULL,
    v1 INTEGER NOT NULL,
    v2 INTEGER NOT NULL,
    v3 DOUBLE PRECISION NOT NULL
)
STORED AS parquet
LOCATION '/Users/yongting/data/G1_1e8_1e8_100_0.parquet';

select id2, id4, power(corr(v1, v2), 2) as r2 from h2o_100m group by id2, id4;

Result

Main: 12s
This PR: 4s
(On my MacBook with m4 pro)

---

Remaining tasks

• Implement convert_to_states()

What changes are included in this PR?

1. Implement two utility functions: accumulate_multiple and accumulate_correlation_states to accumulate states in correlation function. (existing util functions is for aggregate functions with 1 input expr avg(expr1) v.s. corr(expr1, expr2))
2. Implement GroupsAccumulator for corr()

Are these changes tested?

Unit tests for util functions
corr() is covered by existing tests

Are there any user-facing changes?

No

[alamb]

This looks amazing -- thank you @2010YOUY01

I plan to review it over the next day or two

It seems like maybe we should add the data generator for h2o benchmark to the bench.sh script 🤔

[Dandandan]

If passing combined_nulls to NullBuffer::union it will take care of handling Option