feat: support null_treatment, distinct, and filter for window functions in proto

datafusion/proto/proto/datafusion.proto

@@ -518,6 +518,7 @@ message AggregateUDFExprNode {
   LogicalExprNode filter = 3;
   repeated SortExprNode order_by = 4;
   optional bytes fun_definition = 6;
+  optional NullTreatment null_treatment = 7;
 }
 
 message ScalarUDFExprNode {
@@ -538,6 +539,9 @@ message WindowExprNode {
   // repeated LogicalExprNode filter = 7;
   WindowFrame window_frame = 8;
   optional bytes fun_definition = 10;
+  optional NullTreatment null_treatment = 11;
+  bool distinct = 12;
+  LogicalExprNode filter = 13;
 }
 
 message BetweenNode {
@@ -622,6 +626,11 @@ message WindowFrameBound {
   datafusion_common.ScalarValue bound_value = 2;
 }
 
+enum NullTreatment {
+  RESPECT_NULLS = 0;
+  IGNORE_NULLS = 1;
+}
+
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 // Arrow Data Types
 ///////////////////////////////////////////////////////////////////////////////////////////////////
@@ -1365,4 +1374,4 @@ message SortMergeJoinExecNode {
   JoinFilter filter = 5;
   repeated SortExprNode sort_options = 6;
   datafusion_common.NullEquality null_equality = 7;
-}
+}