Invite anonymous user to fill out form

[gabestein]

Motivation

So an admin can send emails with forms to people who create discussions and thus are not members. In this case, it's to create a discussion verification flow for users where we're collecting email addresses.

Requirements

• Allows anyone with a special link to a form to fill it out

Acceptance Criteria

[gabestein]

Let's discuss. Could also see accomplishing this by creating users via API or even action — maybe having a special function that can take an email field and either creates a new user from that field (and sets a member field to that user) or, if the user already exists, sets a member field to that user?