#6249246 Add Siteless Checkout “Thank you completed” page w/ redirect

Changes proposed in this Pull Request

• Created a new getJetpackCheckoutSupportTicketStatus selector to retrieve the status of the “Submit site url” request.
• On the siteless checkout onboarding UI (siteless thank you page), I made the UI respond to the ‘pending’, ‘completed’, and ‘failed’ states when submitting the site url.
  • Disable submit button when request is ‘pending’.
  • Make submit button “Busy” when request is ‘pending’
  • Display error message below input field when request is ‘failed’.
  • Redirect to the “Thank you completed” page when request is ‘success’. – Redirect to: /checkout/jetpack/thank-you-completed/no-site/:product_slug
• Created route & controller for new “Thank you completed” page route (/checkout/jetpack/thank-you-completed/no-site/:product_slug)
• Created the JetpackCheckoutSitelessThankYouCompleted page component and SCSS styles.

Asana task: 1200479326344990-as-1200597353180730

Testing instructions

To simply view the UI:

1. Download this PR.
2. Edit the config/development.json file and enable the jetpack/siteless-checkout feature flag.
3. Start Calypso with yarn start. You need to do this since this PR introduces a new feature flag.
4. Go to http://calypso.localhost:3000/checkout/jetpack/thank-you-completed/no-site/jetpack_scan
5. Verify the page looks looks good, like the Figma mockup listed in the Asana task (linked above), and verify all the SCSS styles look ok for desktop and mobile views.

To test the “Submit site URL” error behaviors & success redirect to the new UI:

1. Patch your sandbox with D63168-code.
2. Patch your sandbox with D63915-code.
3. Sandbox public-api.wordpress.com.
4. Download this PR.
5. Edit the config/development.json file and enable the jetpack/siteless-checkout feature flag.
6. Start Calypso with yarn start. You need to do this since this PR introduces a new feature flag.
7. Complete the siteless checkout flow.
8. When you get to the Siteless Onboarding UI (the thank you page), enter a non-valid url (like a random string) into the input box and submit.
9. Verify the submit button has a “busy” state when submitting.
10. Verify you receive an error message underneath the input box.
11. Now submit a valid site url.
12. Verify that you are redirected to the new “Thank you completed” UI page.
13. Verify the page looks like the Figma mockup listed in the Asana task (linked above)

Screenshot: