fix main loader and back button hero tag (#45)

Author: BenjaminCanape

lib/main.dart

@@ -115,7 +115,7 @@ class MyApp extends HookConsumerWidget {
       future: provider.getJwt(),
       builder: (context, snapshot) {
         if (snapshot.connectionState == ConnectionState.waiting) {
-          return UIUtils.loader;
+          return buildMaterialApp(Center(child: UIUtils.loader));
         } else if (snapshot.hasData && snapshot.data != null) {
           return buildMaterialApp(const HomeScreen());
         } else {

lib/presentation/common/core/utils/ui_utils.dart

@@ -31,6 +31,7 @@ class UIUtils {
   /// A function that create the back button
   static FloatingActionButton createBackButton(BuildContext context) {
     return FloatingActionButton(
+      heroTag: 'back_button',
       backgroundColor: ColorUtils.main,
       elevation: 4.0,
       child: Icon(

lib/presentation/settings/screens/edit_profile_screen.dart

@@ -144,6 +144,7 @@ class EditProfileScreen extends HookConsumerWidget {
                           bottom: 16,
                           right: 80,
                           child: FloatingActionButton(
+                            heroTag: 'save_button',
                             backgroundColor: ColorUtils.main,
                             elevation: 4.0,
                             child: Icon(