StatisticsResult: container for pairwise statistical metric tables

Returned by [compute_pairwise()] and (lazily) by `statistics()` on a `RegionResult`. Holds five tables:

Slots

jaccard

NxN named matrix of Jaccard indices.

dice

NxN named matrix of Sorensen-Dice coefficients.

overlap_coefficient

NxN named matrix of Szymkiewicz-Simpson overlap coefficients.

fold_enrichment

NxN named matrix of fold-enrichment values.

hypergeometric

Long-form data.frame (one row per set pair) with columns: set_a, set_b, intersection, expected, p_value, p_adjusted, significant, highly_significant.