[BugFix](Es Catalog) fix bug that es catalog will return error when q…

…uery partial columns (apache#22423)

Bug：
When the value of some ES column is empty, querying these value in doc_values mode will receive an error.

Reson：
In doc values mode, these values are empty, We need to determine if the array is empty

be/src/exec/es/es_scroll_parser.cpp

@@ -489,8 +489,10 @@ Status ScrollParser::fill_columns(const TupleDescriptor* tuple_desc,
             // because of reading value from _source, we can not process all json type and then just transfer the value to original string representation
             // this may be a tricky, but we can work around this issue
             std::string val;
-            if (pure_doc_value && !col.Empty()) {
-                if (!col[0].IsString()) {
+            if (pure_doc_value) {
+                if (col.Empty()) {
+                    break;
+                } else if (!col[0].IsString()) {
                     val = json_value_to_string(col[0]);
                 } else {
                     val = col[0].GetString();
@@ -588,8 +590,10 @@ Status ScrollParser::fill_columns(const TupleDescriptor* tuple_desc,
                 data.assign_from_double(col.GetDouble());
             } else {
                 std::string val;
-                if (pure_doc_value && !col.Empty()) {
-                    if (!col[0].IsString()) {
+                if (pure_doc_value) {
+                    if (col.Empty()) {
+                        break;
+                    } else if (!col[0].IsString()) {
                         val = json_value_to_string(col[0]);
                     } else {
                         val = col[0].GetString();