unify look of ListTiles

management/lib/pages/users_page.dart

@@ -79,15 +79,25 @@ class _UsersPageState extends State<UsersPage> {
                   (User user) => CardListTile(
                     leading: Icon(user.scope == 'admin' ? Icons.verified_user : Icons.person),
                     title: Text(user.fullName),
+                    onLongPress: () => showDialog(
+                      context: context,
+                      builder: (BuildContext context) => SimpleDialog(
+                        children: [
+                          ListTile(
+                            enabled: user.username != Provider.of<AuthApi>(context).user?.username,
+                            title: const Text('Löschen'),
+                            onTap: () async {
+                              Navigator.of(context).pop();
+                              await _onDeleteUser(user);
+                            },
+                          ),
+                        ],
+                      ),
+                    ),
                     actions: [
-                      if (user.username != Provider.of<AuthApi>(context).user?.username)
-                        IconButton(
-                          onPressed: () => _onDeleteUser(user),
-                          icon: const Icon(Icons.delete_forever_rounded),
-                        ),
                       IconButton(
                         onPressed: () => _onEditUser(user: user),
-                        icon: const Icon(Icons.settings),
+                        icon: const Icon(Icons.edit),
                       ),
                     ],
                   ),
@@ -122,7 +132,7 @@ class _UsersPageState extends State<UsersPage> {
     }
   }
 
-  void _onDeleteUser(User user) async {
+  Future<void> _onDeleteUser(User user) async {
     final result = await showDialog(
       context: context,
       builder: (BuildContext context) => DeleteDialog(name: user.username),