Automated emails to subjects on privacy request updates

[adriaaaa]

Description

We have configured the email content in 1109. This story is to ensure that subjects receive the configured emails

To do: will need designs for what the emails should look like right now.

Assumptions

• Advanced styling and customization of emails are not included in the scope of this ticket, but will be considered in a future feature

Acceptance Criteria

1. Show that a subject receives an email for each phase of their request and that the content matches what is configured by the admin user.
   -- Receipt of a request
   -- When the request was reviewed (and outcome of the review)
   -- When the request starts processing
   -- Completion of the request (+ data package link for access requests)

2. Each notification should come with its own config variable, e.g.
   -- FIDESOPS__NOTIFICATIONS__SEND_REQUEST_RECEIPT_NOTIFICATION
   -- FIDESOPS__NOTIFICATIONS__SEND_REQUEST_REVIEW_NOTIFICATION
   -- FIDESOPS__NOTIFICATIONS__SEND_REQUEST_PROCESSING_NOTIFICATION
   -- FIDESOPS__NOTIFICATIONS__SEND_REQUEST_COMPLETION_NOTIFICATION

Mockups