Extend column statistics analysis to include columns with GroupByColumns

This commit fixes an issue where the cardinality of a column would result in zero if the column had `GroupByColumns` specified and `IsAvailableInMDX=FALSE`. This occurred because statistics for columns with IsAvailableInMDX set to FALSE are not available in the DMV $SYSTEM.DISCOVER_STORAGE_TABLES (see WHERE LEFT(TABLE_ID, 2) = 'H$' in PopulateColumnsCardinality)

Author: albertospelta

src/Dax.Model.Extractor/StatExtractor.cs

@@ -257,7 +257,7 @@ private void LoadColumnStatistics(bool analyzeDirectQuery, DirectLakeExtractionM
                  // skip direct query tables if the analyzeDirectQuery is false
                  where t.Columns.Count > 1 && (analyzeDirectQuery || !t.HasDirectQueryPartitions)   
                      from c in t.Columns
-                     where c.State == "Ready" && !c.IsRowNumber && c.GroupByColumns.Count == 0
+                     where c.State == "Ready" && !c.IsRowNumber
                         // only include the column if the table does not have Direct Lake partitions or if they are resident or if analyzeDirectLake is true
                         && (!t.HasDirectLakePartitions 
                             || (analyzeDirectLake >= DirectLakeExtractionMode.ResidentOnly && c.IsResident)