#11099086 Expose Hosting Trial: Allow starting free trial from themes upload page

Related to Automattic/dotcom-forge#5097

Proposed Changes

This PR allow the user to start a free trial from the themes upload page. There is an issue where we gets redirected to crowdsignal after the atomic transfer. what should happen is that we should be redirected to /wp-admin/theme-install.php

• Show free trial banner when user is eligible
• Shows the trial acknowledge modal and start the trial

Testing Instructions

• go to /themes/upload/simple_site
• Start your free trial and verify the site transitions to atomic successfully

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• https://wpcalypso.wordpress.com/devdocs/docs/testing/index.md for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the “[Status] String Freeze” label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
• For changes affecting Jetpack: Have we added the “[Status] Needs Privacy Updates” label if this pull request changes what data or activity we track or use (p4TIVU-ajp-p2)?