Complete refactor (#123)

src/app/state/LocalStorageProperty.ts

@@ -0,0 +1,14 @@
+import { Property } from './Property'
+
+export class LocalStorageProperty extends Property<string> {
+  constructor(private id: string, fallback: string) {
+    super(localStorage.getItem(id) ?? fallback)
+  }
+  set(value: string) {
+    super.set(value)
+    localStorage.setItem(this.id, value)
+  }
+  get(): string {
+    return this.value
+  }
+}