Fix

Add email signup screen as described in #7138. The new SignupEmailFragment class is similar to the LoginEmailFragment class, but not entirely. We can create a BaseEmailFragment class to help abstract common code as an optimization when we move the signup code into the WordPressLoginFlow library. I chose not to do that at this time to avoid conflicts with ongoing development. The "Continue to magic link" message denotes the flow that will be handled in the subsequent magic link issue.

Test

0. Clear app data.
1. Tap Sign Up button.
2. Tap Sign Up with Email button.
3. Enter email address associated with WordPress.com account.
4. Notice message and login flow.
5. Tap back arrow.
6. Enter email address not associated with WordPress.com account.
7. Notice "Continue to magic link" message.