Add web front-end and fix API issues

node_modules/rxjs/dist/esm/internal/util/Immediate.js

@@ -0,0 +1,30 @@
+let nextHandle = 1;
+let resolved;
+const activeHandles = {};
+function findAndClearHandle(handle) {
+    if (handle in activeHandles) {
+        delete activeHandles[handle];
+        return true;
+    }
+    return false;
+}
+export const Immediate = {
+    setImmediate(cb) {
+        const handle = nextHandle++;
+        activeHandles[handle] = true;
+        if (!resolved) {
+            resolved = Promise.resolve();
+        }
+        resolved.then(() => findAndClearHandle(handle) && cb());
+        return handle;
+    },
+    clearImmediate(handle) {
+        findAndClearHandle(handle);
+    },
+};
+export const TestTools = {
+    pending() {
+        return Object.keys(activeHandles).length;
+    }
+};
+//# sourceMappingURL=Immediate.js.map