## Description
This PR adds the possibility for hspec tests to start a remote server with a custom schema, using the _morpheus_ library. In addition, it adds:
- X-to-DB object relationships tests
- X-to-DB array relationships tests
- X-to-RS relationships tests
For now, all those X are only postgres, but the tests are written in a way that will allow for it to easily be any other DB, or even remote schemas. The actual tests were taken mostly from #3069.
To achieve this, this PR heavily refactors the test harness. Most importantly: it generalizes the notion of a `Backend` to a notion of generic `Context`, allowing for contexts that are the unions of two backends, or of a backend and a remote schema.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/3567
Co-authored-by: jkachmar <8461423+jkachmar@users.noreply.github.com>
GitOrigin-RevId: 623f700ba482743f94d3eaf659e6cfa22cd0dbc9
