refs https://github.com/TryGhost/Team/issues/1418
- adds "Last seen" option to members filtering that lets you filter by date a member last logged in or opened an email with `before`, `on or before`, `on or after`, and `after` options
- adds "Last seen on x" data to the member details screen
No issue
- Changed the Member details page to be more scalable and flexible, depending on whether creators are using subscriptions, emails, and stats.
* Hidden email stats on member detail page when subscriptions are off
* Hid subscription box on member details page when Stripe is not connected
* Updated copy and layout of member details page
* Updated old activity feed styles on member page
* Fixed padding issue for empty activity feed
* Fixed current and new activity feed
* Added Last seen to member details page behind feature flag
* Updated lint todo file
* Fixed spacing issue in member details
refs https://github.com/TryGhost/Team/issues/1277
- extracted member details display into a `<GhMemberDetails>` component for re-use in the member details and members-activity screens
- added loading of member record from the member id query param and displayed the member details above the table when a member filter is present
- hid the member column in the events table when a member filter is present
- it's useless/repeated info at that point
