feat: notifications (#1947)

* feat: notifications
* feat: watchers

* improvements

* handle page move for watchers

* make watchers non-blocking

* more

apps/server/src/core/notification/dto/notification.dto.ts

@@ -0,0 +1,13 @@
+import { IsArray, IsOptional, IsUUID } from 'class-validator';
+
+export class NotificationIdDto {
+  @IsUUID()
+  notificationId: string;
+}
+
+export class MarkNotificationsReadDto {
+  @IsArray()
+  @IsUUID(undefined, { each: true })
+  @IsOptional()
+  notificationIds?: string[];
+}