Dialog: Scroll lock should be optional

[flore2003]

As a developer, it would be great if the scroll lock behavior of the Dialog component could be optionally turned off.

My current use case is creating a cookie consent modal that still allows the user to scroll the page behind it, but I could imagine that there are many other use cases, where scroll locking is not needed or wanted for a given dialog.

If wanted, I could draft up a quick pull request with the needed changes.

[flore2003]

I just realized that there is another discussion with this topic. Please disregard this then.