Chore: convert "unnamed" into constant

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

src/components/EntitySummaryButton.vue

@@ -62,6 +62,7 @@ import { Component, Prop, Vue } from "vue-facing-decorator";
 import EntityIcon from "./EntityIcon.vue";
 import ProjectIcon from "./ProjectIcon.vue";
 import { Contact } from "../db/tables/contacts";
+import { UNNAMED_ENTITY_NAME } from "@/constants/entities";
 
 /**
  * Entity interface for both person and project entities
@@ -163,7 +164,7 @@ export default class EntitySummaryButton extends Vue {
     
     // If the entity is the special "Unnamed", use "Unnamed"
     if (this.entity?.did === "") {
-      return "Unnamed";
+      return UNNAMED_ENTITY_NAME;
     }
     
     // If the entity does not have a set name, but is not the special "Unnamed", use their DID