Feedback to customer on reviews

Problem/Motivation

Two scenarios:

1. When you have a critical review that is valid but you need to communicate with the customer about it because it has language or other issues that the customer needs to resolve. The review can be unpublished or left unpublished but there isn't a mechanism to tell a customer what they need to do to get it accepted.
2. When you want to leave public feedback to reviews.

Proposed resolution

Add a leave feedback operation for reviews. The customer gets a notification of this feedback via email(?). Checkbox to choose if this is public or only visible to the customer. Going back to the feedback form allows editing the message later.

Remaining tasks

User interface changes

API changes

Data model changes