#7720124 Include Boost in product removal confirmation dialog

Proposed Changes

• While cancelling a Jetpack Boost plan or Jetpack Complete, warn user that they will miss out on Boost features

Testing Instructions

• Purchase Boost premium on a test site
• While running calypso locally access your purchases http://calypso.localhost:3000/me/purchases
• Remove the plan
• The removal dialog should mention Boost is being removed
• Purchase Jetpack Complete
• Remove the plan
• The removal dialog should mention Boost is being removed

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests 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)?

Related to Automattic/boost-cloud#158