feat: Avatar decoration (#12096)

* wip

* Update ja-JP.yml

* Update profile.vue

* .js

* Update home.test.ts

packages/backend/src/models/User.ts

@@ -138,6 +138,11 @@ export class MiUser {
 	})
 	public bannerBlurhash: string | null;
 
+	@Column('varchar', {
+		length: 512, array: true, default: '{}',
+	})
+	public avatarDecorations: string[];
+
 	@Index()
 	@Column('varchar', {
 		length: 128, array: true, default: '{}',