[TwigComponent] Change component naming standard + optional name

[weaverryan]

Q	A
Bug fix?	no
New feature?	yes
Tickets	None
License	MIT

Changes the naming convention of components to upper camel case + makes the name argument optional (defaults to class name). Components now look like:

    #[AsTwigComponent]
    class Alert
    {
        public string $type = 'success';
        public string $message;
    }

The template is templates/components/Alert.html.twig and you render with {{ component('Alert') }}. This removes the need for the user to invent & keep track of an arbitrary name, but they can still pass a name to AsTwigComponent. No BC break on this.

Relates to a conversation on #771 (comment)

TODO:

• Update MakerBundle to follow this convention

[WebMamba]

I actually always follow this convention. This felt way more natural to have the same name on the PHP files and on the views side. So 100% agree here.