getFacetedUniqueValues
fun <TData> getFacetedUniqueValues(): (table: Table<TData>, columnId: String) -> () -> Map<Any?, Int>
Builds the per-column faceted-unique-values factory. The returned function is invoked once per (table, columnId) pair and produces a memoised getter for a value -> count map. Iteration order matches the order each value was first seen.