Description

There should be a place to allow to an user to unsubscribe provided email from newsletter.

Acceptance criteria

• there is a dedicated page for such action, like another menu in "my account" for logged in users
• consider the feature to be available for guest customers too (if it make sense and it's possible to do so)
• POST /newsletter/unsubscribe is used to Remove a newsletter subscription for given email:
  request's payload:

{
  "email": "string"
}