add dispose to files to remove controllers when not used

Frontend/patient_manager/lib/components/popUpMessages/mihWarningMessage.dart

@@ -167,6 +167,12 @@ class _MIHDeleteMessageState extends State<MIHWarningMessage> {
     return messageTypes[type];
   }
 
+  @override
+  void dispose() {
+    // TODO: implement dispose
+    super.dispose();
+  }
+
   @override
   Widget build(BuildContext context) {
     var size = MediaQuery.of(context).size;