From T317595: Investigate: Can we load the Create account / Login forms in a modal from an article page?

The dialog that will be implemented in T319504: Show a dialog on the article page when an anonymous user tries to make an edit should be one of the out of the box ones. afaik, that won't work for the form we eventually want to implement. Please:

1. Confirm that this functionality is not available via dialogs as-is
2. If necessary, extend the dialog so that we can include a form in the modal content area

As part of your solution, you should decide if it'll be easier to 1. enforce a structured data schema that parses into a form or 2. allow for injection of a form via jQuery. I suspect 2 but it's up to you!