Create streamlined invited guest onboarding workflow

[avishkar58]

trafficstars

At the moment, when we add a new invited guest to Baobab who doesn't already have an account, it sends them an email with a complicated set of instructions to set a password, update their profile and then register. Create a front-end that streamlines this process by composing the various components into a multi-step form that guides users through the steps with some friendly text.

[avishkar58]

In addition to this, we should track who has accepted their invitation and who hasn't. Add a status indicator on the invited guests page (pending, accepted, expired) and the option to resend the invitation if it has expired.