Remove notifications for packages that are ignored

[fricklerhandwerk]

As a user of the security tracker, I don't want to get notified about suggestions where my package was removed in triaging.

Acceptance criteria

Given I'm subscribed to a set of packages,
When a subset of those is linked in a suggestion and another subset of them later ignored,
Then the second subset does not show up in the corresponding notification.

Given I'm subscribed to a set of packages,
When a subset of those is linked in a suggestion and all of it later ignored,
Then the notification with that suggestion is removed entirely.

Depends on:

• Show subscribed-to packages in notification #835