#7375732 Woo Onboarding: Add email verification functionality

Proposed Changes

• Clicking on the “Resend email verification” button should send a verification email.
• If the email has already been verified or if there’s another failure, an error message should be displayed.
• The button text should change to provide user feedback.

Visuals

Testing Instructions

• Switch to this PR, navigate to /setup/wooVerifyEmail?siteSlug=[your site slug]&flags=signup/woo-verify-email
• Test both with an account that has not yet been verified and one that has.
• If the email needs verification, the button should display “Sending…” then “Request sent!”
• If the email can’t be verified, an error message should be shown.

Fixes #64163 #64461