added unfocus when tapping outside textfield

lib/view/pages/talk/components/chatTextfield.dart

@@ -156,6 +156,9 @@ class _ChatTextfieldState extends State<ChatTextfield> {
                       }
                       setDraft(text);
                     },
+                    onTapOutside: (PointerDownEvent event) {
+                      FocusScope.of(context).requestFocus(FocusNode());
+                    },
                   ),
                 ),
                 const SizedBox(width: 15),