Add built-in operator statistics providers

Adds chain-of-responsibility providers for common physical operators:

- FilterStatisticsProvider: selectivity-based output estimation using
  pre-enhanced child statistics, with post-filter NDV adjustment
- ProjectionStatisticsProvider: passthrough with column mapping
- PassthroughStatisticsProvider: cardinality-preserving operators
  (Sort, Repartition, Window, etc.) via CardinalityEffect
- AggregateStatisticsProvider: NDV-product estimation for GROUP BY,
  delegates for Partial mode and multiple grouping sets (apache#20926)

Author: asolimando

datafusion/physical-plan/src/filter.rs

@@ -340,7 +340,7 @@ impl FilterExec {
     }
 
     /// Calculates `Statistics` for `FilterExec`, by applying selectivity (either default, or estimated) to input statistics.
-    fn statistics_helper(
+    pub(crate) fn statistics_helper(
         schema: &SchemaRef,
         input_stats: Statistics,
         predicate: &Arc<dyn PhysicalExpr>,