Send updated user folder permissions to the API

Integrates the folder permissions form with the updated API endpoint
to store changes in the user folders.

Since user folder permissions are returned in the full list of template
folders for the service we need to invalidate the cache key for it each
time we update user permissions.

app/main/views/manage_users.py

@@ -87,6 +87,10 @@ def edit_user_permissions(service_id, user_id):
     form = PermissionsForm.from_user(
         user,
         service_id,
+        folder_permissions=[
+            f['id'] for f in current_service.all_template_folders
+            if user_id in f.get('users_with_permission', [])
+        ],
         all_template_folders=current_service.all_template_folders
     )
 
@@ -94,6 +98,10 @@ def edit_user_permissions(service_id, user_id):
         user_api_client.set_user_permissions(
             user_id, service_id,
             permissions=form.permissions,
+            folder_permissions=(
+                form.folder_permissions.data
+                if current_service.has_permission('edit_folder_permissions') else None
+            ),
         )
         if service_has_email_auth:
             user_api_client.update_user_attribute(user_id, auth_type=form.login_authentication.data)