feature dev: fix code gen panel showing "Generating code" alongside code result (#1591)

Problem:
- A new update of mynah UI seems to have caused an issue where when the code result gets created it doesn't override the previous body text

Solution:
- Make sure we're sending an empty body so no text gets shown after "Generating code" has finished

Author: jpinkney-aws

packages/core/src/amazonq/webview/ui/apps/featureDevChatConnector.ts

@@ -149,6 +149,7 @@ export class Connector {
                     filePaths: messageData.filePaths,
                     deletedFiles: messageData.deletedFiles,
                 },
+                body: '',
             }
             this.onChatAnswerReceived(messageData.tabID, answer)
         }