Add importCompleted notification. Send importCompleted when antenna/customEmoji/muting/userList is imported

The only userImportableEntities that don't notify
are blocking and following because they fork off a batch of single

Closes #891

packages/backend/src/models/json-schema/notification.ts

@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { notificationTypes, userExportableEntities } from '@/types.js';
+import { notificationTypes, userExportableEntities, userImportableEntities } from '@/types.js';
 
 const baseSchema = {
 	type: 'object',
@@ -334,6 +334,26 @@ export const packedNotificationSchema = {
 				format: 'id',
 			},
 		},
+	}, {
+		type: 'object',
+		properties: {
+			...baseSchema.properties,
+			type: {
+				type: 'string',
+				optional: false, nullable: false,
+				enum: ['importCompleted'],
+			},
+			importedEntity: {
+				type: 'string',
+				optional: false, nullable: false,
+				enum: userImportableEntities,
+			},
+			fileId: {
+				type: 'string',
+				optional: false, nullable: false,
+				format: 'id',
+			},
+		},
 	}, {
 		type: 'object',
 		properties: {