This is refactoring all our fragments and fixing the warning about an
existing name `user`. Apparently, fragments should have a unique name
globally.
I decided to call `userFragment`, `postFragment` the fragments for one
object and use different names to query for related objects.
I would be glad to learn a better way to handle this.
- Add pin/unpin post to content menu
- Update apollo cache to reactively unpin
- Update apollo cache in root path to re-order Posts
- Order with pinned post first
- Start setting up filters, so that the pinned post is always the first
post visible