Render id={form.identifier} around ConfirmationFinisher

[paavo]

The <form> is rendered always withid={form.identifier}
After submitting the Form #{form.identifier} will be added to the URL.
If the Form is somewhere on the Page, the anchor #{form.identifier} will jump to the Form.

The Neos.Form.Builder:ConfirmationFinisher does NOT render id={form.identifier} around.
Because of the missing id, the Browser doesn't jump to the Confirmation Message and it maybe get lost somewhere on the page.

What about wrapping an id={form.identifier} around the Builder:ConfirmationFinisher?

I created a PR to fix this: #129