Add statistic expression

[gatesn]

Per the epic #7707

This PR adds an expression that returns the requested statistic, blown out for each row. When run against a single array, this returns a ConstantArray. When run against ChunkedArray, it returns RunEnd stats.

It will be used by pluggable Falsify/Verify rewrite rules to allow for the workflow of adding custom aggregate functions to zone maps for falsification checks, e.g. bloom filters.

[codspeed-hq]

Merging this PR will improve performance by 12.74%

⚠️ Unknown Walltime execution environment detected

Using the Walltime instrument on standard Hosted Runners will lead to inconsistent data.

For the most accurate results, we recommend using CodSpeed Macro Runners: bare-metal machines fine-tuned for performance measurement consistency.

⚡ 2 improved benchmarks
✅ 1206 untouched benchmarks

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
⚡	Simulation	take_map[(0.1, 0.5)]	1,111.5 µs	985.9 µs	+12.74%
⚡	Simulation	take_map[(0.1, 1.0)]	1.8 ms	1.6 ms	+11.49%

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_{Comparing ngates/stats-expr (ec42e75) with develop (ff12040)}