Allow GET method for the Payload /api/graphql GraphQL route to allow using caceheable responses

[MurzNN]

I found out that Payload CMS surprisingly does not accept GraphQL requests with the GET method, they work only with POST method. With GET - Payload produces a "405 Method Not Allowed" error on the /api/graphql endpoint.

Many GraphQL client libraries switched to use GET for simple GraphQL queries by default, to receive caching and other performance benefits.

So, can we just simply allow the GET method in the /api/graphql endpoint to accept GraphQL requests? Or will this require some other changes on the backend?