- `edge_nodes` needs to get called on the object
- added `include GlobalID::Identification` in a couple places
- renamed `object` to `item` in spec due to conflict
This adds Keyset pagination to GraphQL lists. PoC for that is
pipelines on merge requests and projects.
When paginating a list, the base-64 encoded id of the ordering
field (in most cases the primary key) can be passed in the `before` or
`after` GraphQL argument.
