[Meta] GraphQL Client

Problem/Motivation

Extend base API client class to create a GraphQL Client comparable to our JSON:API Client

Proposed resolution

For the scope of our pitch-burgh commitment I'm initially just doing prep work to make contribution possible. Aiming to scaffold out the package and the broad strokes of the meta issue.

We can then prioritize further development based on interest.

Remaining tasks

* Scaffold package.
* Create child issues under meta issue.

API changes

New graphql-client package