Add web front-end and fix API issues

node_modules/rxjs/dist/esm/internal/operators/distinctUntilKeyChanged.js

@@ -0,0 +1,5 @@
+import { distinctUntilChanged } from './distinctUntilChanged';
+export function distinctUntilKeyChanged(key, compare) {
+    return distinctUntilChanged((x, y) => (compare ? compare(x[key], y[key]) : x[key] === y[key]));
+}
+//# sourceMappingURL=distinctUntilKeyChanged.js.map