add dispose to files to remove controllers when not used

Frontend/patient_manager/lib/pages/patientAdd.dart

@@ -309,6 +309,24 @@ class _AddPatientState extends State<AddPatient> {
     }
   }
 
+  @override
+  void dispose() {
+    idController.dispose();
+    fnameController.dispose();
+    lnameController.dispose();
+    cellController.dispose();
+    emailController.dispose();
+    medNoController.dispose();
+    medNameController.dispose();
+    medSchemeController.dispose();
+    addressController.dispose();
+    medAidController.dispose();
+    medMainMemController.dispose();
+    medAidCodeController.dispose();
+    _focusNode.dispose();
+    super.dispose();
+  }
+
   @override
   void initState() {
     medAidController.addListener(isRequired);