chore: Output BaseAggregateExec accurate unsupported names

Author: comphead

spark/src/main/scala/org/apache/comet/serde/QueryPlanSerde.scala

@@ -1440,12 +1440,22 @@ object QueryPlanSerde extends Logging with CometExprShim {
           return None
         }
 
-        val groupingExprs = groupingExpressions.map(exprToProto(_, child.output))
-        if (groupingExprs.exists(_.isEmpty)) {
-          withInfo(op, "Not all grouping expressions are supported")
+        val groupingExprsWithInput =
+          groupingExpressions.map(expr => expr.name -> exprToProto(expr, child.output))
+
+        val emptyExprs = groupingExprsWithInput.collect {
+          case (expr, proto) if proto.isEmpty => expr
+        }
+
+        if (emptyExprs.nonEmpty) {
+          withInfo(
+            op,
+            s"Not all grouping expressions are supported. Unsupported: ${emptyExprs.mkString(", ")}")
           return None
         }
 
+        val groupingExprs = groupingExprsWithInput.map(_._2)
+
         // In some of the cases, the aggregateExpressions could be empty.
         // For example, if the aggregate functions only have group by or if the aggregate
         // functions only have distinct aggregate functions: