Raise visibility of getTableKind (#220)

In case of multiple results - e.g.: `ClientImpl.execute("print 1; print 2")` the `KustoOperationResult.resultTables` will contain two tables with kind `WellKnownDataSet.PrimaryResult`.
While `KustoOperationResult.getPrimaryResults` will always give us the first one, in order for us to retrieve the second one (or more) we need to iterate through all the `KustoOperationResult.resultTables`, and since it contains metadata tables we need to be able to filter it by `WellKnownDataSet` - but we can't since `getTableKind` is package-private. 
Raising its visibility to public will allow us to achieve what we need.

Co-authored-by: Yihezkel Schoenbrun <yischoen@microsoft.com>

data/src/main/java/com/microsoft/azure/kusto/data/KustoResultSetTable.java

@@ -59,6 +59,10 @@ public class KustoResultSetTable {
         return tableId;
     }
 
+    public WellKnownDataSet getTableKind() {
+        return tableKind;
+    }
+    
     public KustoResultColumn[] getColumns() {
         return columnsAsArray;
     }
@@ -71,10 +75,6 @@ public class KustoResultSetTable {
         this.tableKind = tableKind;
     }
 
-    WellKnownDataSet getTableKind() {
-        return tableKind;
-    }
-
     protected KustoResultSetTable(JSONObject jsonTable) throws KustoServiceQueryError {
         tableName = jsonTable.optString(TABLE_NAME_PROPERTY_NAME);
         tableId = jsonTable.optString(TABLE_ID_PROPERTY_NAME);