Don't register listener for custom directive

[calebporzio]

Livewire supports "wildcard" event listeners like this:

<div wire:some-event="someMethod">...</div>

If what comes after wire: isn't a built-in directive, Livewire will register an event listener for it and fire the method when the event is fired. (This is actually how wire:click itself works - it's just a wildcard event)

However, if you register a custom directive like this:

Livewire.directive('sort', ({ ... }) => { ... })

Livewire will encounter <div wire:sort and not only run your custom directive code, but also register a listener for the sort event.

This PR disables that behavior so that errant custom directive names don't cause odd behavior with native events.