Define model for notification preferences

[mehalyna]

Description Define appropriate models to allow users to customize their notification preferences. Create an endpoint for receiving existent notification types.

Possible models

• NotificationTypes

  • name: str # code name of notification
  • description: str # user-friendly notification type description

• NotificationPreferences

  • user_id: int # user identification
  • allowed_notification_types: list # list of references to NotificationTypes (for example)