add arguments file with businessUserScreenArguments object

Frontend/patient_manager/lib/objects/arguments.dart

@@ -0,0 +1,9 @@
+import 'package:patient_manager/objects/appUser.dart';
+import 'package:patient_manager/objects/businessUser.dart';
+
+class BusinessUserScreenArguments {
+  final AppUser signedInUser;
+  final BusinessUser? businessUser;
+
+  BusinessUserScreenArguments(this.signedInUser, this.businessUser);
+}