Feat: Option to send credentials with http requests

[npflood]

Fixes #1062

This PR implements the ability to set the withCredentials value for HTTP requests via a configuration option. https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/withCredentials

This is important as it is often necessary to set this value to true if a token request also returns cookies. Providing refresh tokens as secure cookies is considered by many to be a best-practice. https://hasura.io/blog/best-practices-of-using-jwt-with-graphql/