Benchmark window function with multiple partitioning columns

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Add benchmark exposing

• Exponential planning time when window function is partitioned by multiple columns #17401

The benchmark can be run with

cargo bench --bench sql_planner -- physical_window_function_partition

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Results on current main on my busy laptop

physical_window_function_partition_by_4_on_values
time: [485.47 µs 487.78 µs 490.77 µs]
Found 4 outliers among 100 measurements (4.00%)
1 (1.00%) high mild
3 (3.00%) high severe
physical_window_function_partition_by_7_on_values
time: [22.820 ms 22.891 ms 22.967 ms]
Found 5 outliers among 100 measurements (5.00%)
5 (5.00%) high mild
Benchmarking physical_window_function_partition_by_8_on_values: Warming up for 3.0000 s
Warning: Unable to complete 100 samples in 5.0s. You may wish to increase target time to 9.4s, or reduce sample count to 50.
physical_window_function_partition_by_8_on_values
time: [98.300 ms 100.62 ms 103.25 ms]
Found 14 outliers among 100 measurements (14.00%)
5 (5.00%) high mild
9 (9.00%) high severe

(On DF 45, all times are in microseconds.)