Fix input clearable button to also dispatch change event

[joshhanley]

The scenario

If you have a date pciker with an input that has the clearable attribute, currently pressing the clear button will clear the input value but won't update the value stored by Livewire.

<?php

use Livewire\Volt\Component;

new class extends Component {
    public $date;
};
?>

<div>
    <flux:text>Date: {{ $date }}</flux:text>
    <flux:date-picker
        wire:model.live="date"
    >
        <x-slot name="trigger">
            <flux:date-picker.input clearable />
        </x-slot>
    </flux:date-picker>
</div>

The problem

The problem is that the clear button only dispatches an input event but the date picker is listening for a change event on the input.

The solution

The solution is to update the clearable button to also dispatch a change event, which I have done in this PR. I also refactored the clear button to make it more efficient and readable.

Fixes #1157