Add web front-end and fix API issues

node_modules/rxjs/dist/cjs/internal/observable/iif.js

@@ -0,0 +1,9 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.iif = void 0;
+var defer_1 = require("./defer");
+function iif(condition, trueResult, falseResult) {
+    return defer_1.defer(function () { return (condition() ? trueResult : falseResult); });
+}
+exports.iif = iif;
+//# sourceMappingURL=iif.js.map