perf: optimize array_distinct with batched row conversion

[lyne7-sc]

Which issue does this PR close?

• Closes #.

Rationale for this change

This PR optimizes the array_distinct function by batching value conversions and utilizing a HashSet for deduplication.
It is a follow-up to #20243.

What changes are included in this PR?

This PR optimizes array_distinct by:

1. Converting all values to rows in a single batch rather than individually.
2. Using a HashSet to deduplicate values for each list.

Benchmark

group                                main                                   optimized
-----                                ----                                   ---------
array_distinct/high_duplicate/10     2.66   855.1±28.18µs        ? ?/sec    1.00    321.9±8.70µs        ? ?/sec
array_distinct/high_duplicate/100    2.21      6.4±0.13ms        ? ?/sec    1.00      2.9±0.09ms        ? ?/sec
array_distinct/high_duplicate/50     2.14      3.2±0.05ms        ? ?/sec    1.00  1478.3±41.90µs        ? ?/sec
array_distinct/low_duplicate/10      2.73  1017.3±44.67µs        ? ?/sec    1.00   372.5±17.33µs        ? ?/sec
array_distinct/low_duplicate/100     1.32      4.4±0.13ms        ? ?/sec    1.00      3.3±0.15ms        ? ?/sec
array_distinct/low_duplicate/50      1.55      2.6±0.06ms        ? ?/sec    1.00  1689.0±94.15µs        ? ?/sec

Are these changes tested?

Yes, unit tests exist and pass.

Are there any user-facing changes?

Yes, there is a slight change in the output order. This new behavior is consistent with array_union and array_intersect, where the output order is more intuitive as it preserves the original order of elements in the array.

[Dandandan]

I think as a follow-up, it might reuse the Rows and HashSet allocations between batches.

[lyne7-sc]

Thanks for the suggestion! I'll look into it and try reusing the allocations. Not sure if thread_local will help, but any tips or better approaches you'd recommend?