Remove dead & duplicated code (#11405)

* Remove dead code

* Make dead code happier

* DRY pickle additional data calculation

* Iterate

src/utils/permalinks/PermalinkConstructor.ts

@@ -69,8 +69,4 @@ export class PermalinkParts {
     public get primaryEntityId(): string | null {
         return this.roomIdOrAlias || this.userId;
     }
-
-    public get sigil(): string {
-        return this.primaryEntityId?.[0] || "?";
-    }
 }

src/utils/permalinks/Permalinks.ts

@@ -114,6 +114,7 @@ export class RoomPermalinkCreator {
     }
 
     public start(): void {
+        if (this.started) return;
         this.load();
         this.room?.currentState.on(RoomStateEvent.Update, this.onRoomStateUpdate);
         this.started = true;
@@ -128,10 +129,6 @@ export class RoomPermalinkCreator {
         return this._serverCandidates;
     }
 
-    public isStarted(): boolean {
-        return this.started;
-    }
-
     public forEvent(eventId: string): string {
         return getPermalinkConstructor().forEvent(this.roomId, eventId, this._serverCandidates);
     }