Fix search options not opening on iOS (#549)

* Fix search options not opening on iOS

* cleanup

bookmarks/frontend/behaviors/dropdown.js

@@ -0,0 +1,36 @@
+import { registerBehavior } from "./index";
+
+class DropdownBehavior {
+  constructor(element) {
+    this.element = element;
+    this.opened = false;
+    this.onOutsideClick = this.onOutsideClick.bind(this);
+
+    const toggle = element.querySelector(".dropdown-toggle");
+    toggle.addEventListener("click", () => {
+      if (this.opened) {
+        this.close();
+      } else {
+        this.open();
+      }
+    });
+  }
+
+  open() {
+    this.element.classList.add("active");
+    document.addEventListener("click", this.onOutsideClick);
+  }
+
+  close() {
+    this.element.classList.remove("active");
+    document.removeEventListener("click", this.onOutsideClick);
+  }
+
+  onOutsideClick(event) {
+    if (!this.element.contains(event.target)) {
+      this.close();
+    }
+  }
+}
+
+registerBehavior("ld-dropdown", DropdownBehavior);