Improve copy on email confirmation step

Problem

Webstore registration requires email confirmation, but the screen asking the user to confirm their email emphasizes resending the confirmation email, not the the main action of checking your email to click the confirmation link.

It also doesn't tell user why confirmation is required (because we send the license to that email and we need to make sure it's right).

Proposal

• Move the info that's currently hidden in the alert down into the main body.
• Add a value prop for the user to tell them why confirming their email is important (something like "We need you to confirm your email so that we send your license to the right place.")
• Give less emphasis to "Resend confirmation instructions" and more emphasis to the action that they really need to take which is "Check your email."

Availability & Testing

Add a value prop for the user to tell them why confirming their email is important

Any associated Vue changes should also be accompanied by frontend Jest test changes to test the new prop, or any other modifications.