Batched requests for remote schemas

We have a remote schema for a google distance matrix API to calculate the travel time to a list of locations, currently it calls this per location.

If there was an option to turn on batched requests to remote schemas we maybe able to reduce the number of calls to this service, for example from 10 (per page) to just 1.

I think the only way we could do this currently would be to have a direct query rather than it being contextual to the location which would mean two separate requests from the front end instead of one, one to get the locations and another to get their travel time.

Apollo server supports batch requests as [Query Batching](https://www.apollographql.com/docs/router/executing-operations/query-batching/).

This has also been mentioned here https://github.com/hasura/graphql-engine/issues/1812 but likely from a client context rather than via remote schema.

Start by reading the remote schema behavior described in the issue and compare it with Apollo Server's Query Batching documentation. Use the Google Distance Matrix example to define how multiple contextual locations would be combined into one request, and review issue #1812 for related prior discussion. Done means remote schemas can optionally batch these requests without requiring separate frontend queries.

Written by the indexing model from the issue text.