Add timeout to GraphQL queries

Summary

There is no timeout on GraphQL queries. The graphql-ruby library allows us to implement a timeout that returns a partial response if the timeout is triggered. The response contains the fields that had a chance to resolve, and anything unresolved is nil.

Potential solution

We can add timeout middleware quite easily using the graphql-ruby library. However, implementing this solution would have to take into account that the frontend must be able to properly handle partial responses.