Creates a new JWT Auth middleware
Checks for an authentication token, saves its content to event.auth and throws errors if anything fishy goes on. It will pass if no authorization header is present, but will ensure that event.auth is undefined in those cases. Authorization or authorization headers will both be checked. If both exist, the middleware will throw an error. If options.tokenSource is set, then that function will be used to retrieve the token and Headers will serve as fallback.
Staticcreate
The actual middleware