Following a change in e9f7262813 which prevents the notification level to be returned from the update endpoint, the model couldn't update itself. This commit makes the update manually and adds a test to prevent future regressions.
Note we could also change the backend endpoint, but this should work correctly with minimum risk.
When a category has default_list_filter=none, there were a number of issues which this commit resolves:
1. When using the breadcrumbs to navigate a `default_list_filter=none` category, adding a tag filter would not apply the no-subcategories filter, but the subcategories dropdown would still say 'none'. This commit adjusts `getCategoryAndTagUrl` so that `/none` is added to the URL
2. When landing on `/tags/c/{slug}/{id}/{tag}`, for a default_list_filter=none category, it would include subcategories. This commit introduces a client-side redirect to match the behavior of `/c/{slug}/{id}`
3. When directly navigating to `/c/{slug}/{id}`, it was correctly redirecting to `/c/{slug}/{id}/none`, BUT it was still using the preloaded data for the old route. This has been happening since e7a84948. Prior to that, the preloaded data was discarded and a new JSON request was made to the server. This commit restores that discarding behavior. In future we may want to look into making this more efficient.
System specs are introduced to provide end-end testing of this functionality
