Enable ShareRemoved Email Notification

[kobergj]

We need to enable receiving ShareRemoved notifications via email. They are already available via In-App Notification, so most logic should be copy/pastable from userlog service.

Acceptance Criteria

• I can enable/disable to receive ShareRemoved notifications for emails in the notification options
• If enabled I receive an email notification when a shared-with-me share is removed
• If disabled I don't receive an email notification when a shared-with-me share is removed.

[kobergj]

Needs to go to 7.1 release - hence prio 1