Fix: Added the ability to download files in the agent message reply function. (#11281)

### What problem does this PR solve?

Fix: Added the ability to download files in the agent message reply
function.

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/agent/constant/index.tsx

@@ -417,6 +417,7 @@ export const initialIterationValues = {
   items_ref: '',
   outputs: {},
 };
+
 export const initialIterationStartValues = {
   outputs: {
     item: {
@@ -845,3 +846,10 @@ export enum JsonSchemaDataType {
   Array = 'array',
   Object = 'object',
 }
+
+export enum ExportFileType {
+  PDF = 'pdf',
+  HTML = 'html',
+  Markdown = 'md',
+  DOCX = 'docx',
+}