Add a temporary check for service folder permission

Since we're calling `User.has_template_folder_permission` directly
in a few places (notably the `folder_path` template macro), we need
to check that the service has the feature flag enabled first. This is
usually done by the caller, but template macro doesn't have access to
`current_service`. To avoid passing it in each time the macro is called
we're adding a temporary check inside the method itself.

This commit can be reverted completely when we remove the service
feature flag.

app/models/user.py

@@ -151,7 +151,15 @@ class User(UserMixin):
     def has_permission_for_service(self, service_id, permission):
         return permission in self._permissions.get(service_id, [])
 
-    def has_template_folder_permission(self, template_folder):
+    def has_template_folder_permission(self, template_folder, service=None):
+        from app import current_service
+
+        if service is None:
+            service = current_service
+
+        if not service.has_permission('edit_folder_permissions'):
+            return True
+
         if self.platform_admin:
             return True