Chore: convert "unnamed" into constant

- "Unnamed/Unknown" simplified into just "Unnamed"
- Phrase variations have their own constants

src/components/PushNotificationPermission.vue

@@ -115,6 +115,7 @@ import { urlBase64ToUint8Array } from "../libs/crypto/vc/util";
 import * as libsUtil from "../libs/util";
 import { logger } from "../utils/logger";
 import { PlatformServiceMixin } from "../utils/PlatformServiceMixin";
+import { UNNAMED_ENTITY_NAME } from "@/constants/entities";
 
 // Example interface for error
 interface ErrorResponse {
@@ -602,7 +603,7 @@ export default class PushNotificationPermission extends Vue {
    * Returns the default message for direct push
    */
   get notificationMessagePlaceholder(): string {
-    return "Click to share some gratitude with the world -- even if they're unnamed.";
+    return `Click to share some gratitude with the world -- even if they're ${UNNAMED_ENTITY_NAME.toLowerCase()}.`;
   }
 
   /**