* init proposal subscribe be and fe
* add subscription email templates
* wire up subscription emails
* email subscribers on proposal milestone, update, cancel
* disallow subscriptions if email not verified
* update spelling, titles
* disallow proposal subscribe if user is team member
* hide subscribe if not signed in, is team member, canceled
* port follow from grant-base
* remove subscribed
* convert subscribed to follower
* backend - update tests
* frontend - fix typings
* finish follower port
* update comment
* fix email button display issues
* init liking backend
* init liking frontend
* fix lint
* add liking backend tests
* refactor like component