fix: do not rely on the `events` package within type definitions and add methods from `event-emitter`

[arturovt]

I've removed the reference to events module within type definitions. The events is a Node.js package, which shouldn't be used since xgplayer is running in the browser.

This also was shipped in package.json as a devDependency, which means @types/events wasn't installed when users ran npm i xgplayer.