Add a Rate Limit to the GraphQL API

[connorshea]

first-party tokens should be exempt from the rate limit because I'm special.

See some other GraphQL APIs and their rate limits for inspiration:

• https://shopify.dev/api/admin-graphql#rate_limits (https://shopify.engineering/rate-limiting-graphql-apis-calculating-query-complexity)
• https://docs.github.com/en/graphql/overview/resource-limitations#rate-limit
• https://anilist.gitbook.io/anilist-apiv2-docs/overview/rate-limiting