Fix paging of changeset resolvers
Created by: eseliger
- Fixes a bug where pages could be underfilled when changesets are filtered because of
!optsSafe
. The db would only return 15 items, but after filtering it could be we serve pages with less than 15 nodes and not being the end page. - Introduces cursor pagination, because I didn't want someone else to need to touch that nasty logic and it's the last connection in our code to not have it afaik.
- Reduces the query count to 1, because we only need 1 compute method now.