Feat: Adding the ability to deregister event listeners

[AndresMonk]

Adds the ability to remove listeners that have been registered.

[CLAassistant]

All committers have signed the CLA.

[michielvandergeest]

Great work @AndresMonk! Love contributions with tests and documentation!

About the implementation:he $removeListener method seems removes events by event type, rather than a single listener by id. Also, if I understood correctly this method will remove all listeners that exists for a specific event. I imagine that beign useful in certain cases, but I can also see how more granular control of which listeners are being removed may come in handy. What do you think?

[AndresMonk]

Thanks @michielvandergeest !

Also, if I understood correctly this method will remove all listeners that exists for a specific event.
That wasn’t what I was gunning for, so it could be my understanding of the maps is a bit wonky.

As a breakdown of how I thought this was working:

//! Get all the components that are listening to this specific event.
let componentsMap = eventsMap.get(event)

...

//! Check if the component exists within the map the event.
if (componentsMap.contains(component)) {

  //! If it does exist, remove this component from the listeners for this event.
  componentsMap.delete(component);

  //! Set the updated list of components for the map.
  eventsMap.set(event, componentsMap)
  callbackCache.delete(event)
}

[michielvandergeest]

No, I think you are actually right! I looked at the implementation to fast :)

[michielvandergeest]

Thanks for making these last changes. This looks good to me!