refs https://github.com/TryGhost/Team/issues/1071
Going forward, if the visibility of a page/post is set for specific tiers, we send a `tiers` array in API response that contains list of tiers with access. This change -
- updates post/page mapper to transform existing data where `visibility` is a custom nql string to tiers array
- updates default include for post/pages to include `products`, which allows attaching relevant tiers from the pivot table
- cleans up usage of `visibility_filter` in serialization
refs: #13380
- this is to replace i18n.t with tpl because i18n.t is deprecated
- Replaced i18n.t with tpl helper in email-post.js
- Replaced i18n.t with tpl helper in email-preview.js
refs https://github.com/TryGhost/Team/issues/990
- Relying on uuid instead of slug makes the posts less discoverable and partially soves discoverability through overriden robots.txt files
refs https://github.com/TryGhost/Team/issues/899
- The internal API is needed to be able to fetch email-only posts through email router. The concept is similar to Preview API with a difference that only posts with `sent` status are accessible and there is content-gating present.