[make:event] Add command for making Event class

[Ippey]

I think adding "make:event" that makes Event class is good, although that is a small feature. So, I wrote a simple make command.

php bin/console make:event


 The name of the event class (e.g. OrderPlacedEvent):
 > ItemCreatedEvent

 Field name (press enter to stop adding fields):
 > id

 Field type (e.g. string) [string]:
 > int

 Field visibility (public, protected, private) [public]:
  [0] public
  [1] private
  [2] protected
 > public

 Can this field be null (nullable) (yes/no) [no]:
 > no

 Field name (press enter to stop adding fields):
 > 

It makes bellow

<?php

namespace App\Event;

use Symfony\Contracts\EventDispatcher\Event;

final class ItemCreatedEvent extends Event
{
    public function __construct(
        public readonly int $id,
    ) {
    }
}