Option to upload query

We would like to use persisted queries, but not automated. It gives us a security benefit, that only the selected queries are allowed for clients.

1. Option to add/upload queries manually, similarly as in graphql module (https://www.drupal.org/docs/8/modules/graphql/query-maps)
2. Add an option to disallow unknown queries

Note: Using the persisted queries option provided by the graphql module is not wanted, as it works with a deprecated apollo package. https://github.com/apollographql/persistgraphql/pull/67