Support existing REST APIs in GraphQL

Make sure all the data and filters available in the REST GET APIs are available in the GraphQL as well.

Can be done only after the GraphQL service is in production

---

Migrated from T4295 (view on Phabricator)

marked this issue as related to #4083

added GraphQL API priority:Normal labels

assigned to @jayeshv

changed the description

added priority:Low label and removed priority:Normal label

added priority:Normal label and removed priority:Low label

added activity::Implementation label

changed milestone to %GraphQL API

changed time estimate to 3w

added 1w of time spent

Mostly done. Pending items can be tracked at #4664 (closed)

closed