chore: refactor service and backend to use REST

Signed-off-by: Heikki Hellgren <heikki.hellgren@op.fi>

plugins/notifications-common/src/types.ts

@@ -14,14 +14,9 @@
  * limitations under the License.
  */
 
-import * as muiIcons from '@material-ui/icons';
-
 /** @public */
 export type NotificationType = 'read' | 'unread' | 'saved';
 
-/** @public */
-export type NotificationIcon = keyof typeof muiIcons;
-
 /** @public */
 export type Notification = {
   id: string;
@@ -29,8 +24,6 @@ export type Notification = {
   title: string;
   description: string;
   link: string;
-  icon?: NotificationIcon;
-  image?: string;
   created: Date;
   read?: Date;
   saved: boolean;