refs https://github.com/TryGhost/Arch/issues/95
Rather than storing all of the relations between the latest collection and
posts, we know that it contains all posts. This means we don't have to keep the
collections posts in sync. Instead we can fetch them from the posts table. This
saves a lot of work during recalculation.
refs https://github.com/TryGhost/Arch/issues/16
- When posts produce PostsBulkUnpublishedEvent the collections having a published_at filter should update the posts belonging to them
The PostRepository type was using `any` (an anti pattern) rather than
`PostCollection`, and we had optional properties, which are not really
optional. This cleans up the types and updates the tests alongside them.
refs https://github.com/TryGhost/Team/issues/3170
- This implementation allows to create an automatic collection with a filter defining automatically populated posts that belong to a collection
- To populate collection using a filter the API client can send a `filter` property along with a collection request
- Filter values are compatible with the filters used in Content API (https://ghost.org/docs/content-api/#filter)
