From the previous commit, we are now showing toasts in the reverse order (latest to oldest).
Next, extend the "hide snack" timer to handle multiple snacks. It will dismiss them one by one, restarting itself until no more toasts.
Show a stacked GUI when there are multiple toasts.
Users can still manually dismiss the toasts.
Initially, the filtered list was done at the component level, and the list was simply a subset of `notifications`. But due to the limit issue explained in 5694, we now query the filtered list instead.
Considerations:
- The filtered list could contain items not listed in the 'All' list. We could add a string at the bottom of 'All' that says "not all items retrieved" if this confuses the user.
- The unseen count needs to be based on 'All' and not the filtered one, so that data needs to be stashed somehow (can't re-use the array).
Use 2 arrays for now instead of trying to accumulate "all" and "filtered" into 1 array.
