feat: pass abortSignal to resolvers (#4261)
this allows e.g. passing the signal to fetch
Note: the `abortSignal` is now the fifth argument to a GraphQLFieldResolverFn. If no resolver if provided, and the parent is an object with a key for the field name with a value that is a function, the `abortSignal` will be the fourth argument, as in the included test, with the `parent` accessible via the `this` keyword.
