Allow to use defined events only

[xmedeko]

As a defensive programmer 😃 I would welcome a switch to allow to use defined events only. Something like:

var emitter = new EventEmitter();
emitter.defineEvents(["my-event-1", "my-event-2"]);
emitter.setValidating(true); // switch on validations

emitter.addListener("my-event-1", () => {...}); // OK
emitter.addListener("bad-event", () => {...}); // Error
emitter.emit("my-event-1"); // OK
emitter.emit("bad-event"); // Error
// etc. other methods like removeEvent