This makes it possible for the test harness to start the test JWK server and the test remote schema server.
In order to do this, we still generate the TLS certificates in the test script (because we need to install the generated CA certificate in the OS certificate store), and then pass the certificate and key paths into the test runner.
Because we are still using _test-server.sh_ for now, we don't use the JWK server fixture in that case, as HGE needs the JWK server to be up and running when it starts. Instead, we keep running it outside (for now).
This is also the case for the GraphQL server fixture when we are running the server upgrade/downgrade tests.
I have also refactored _graphql_server.py_ so there isn't a global `HGE_URLS` value, but instead the value is passed through.
PR-URL: https://github.com/hasura/graphql-engine-mono/pull/6303
GitOrigin-RevId: 06f05ff674372dc5d632e55d68e661f5c7a17c10
