addPortaledMenu function infrastructure

function addPortaledMenu(listboxId: string, options: string[]): HTMLElement {
  const menu = document.createElement("div");
  menu.className = "react-select__menu";

  const menuList = document.createElement("div");
  menuList.className = "react-select__menu-list";

  const listbox = document.createElement("div");
  listbox.id = listboxId;
  listbox.setAttribute("role", "listbox");

  for (const optText of options) {
    const opt = document.createElement("div");
    opt.className = "react-select__option";
    opt.textContent = optText;
    opt.dataset["value"] = optText.toLowerCase();
    listbox.appendChild(opt);
  }

  menuList.appendChild(listbox);
  menu.appendChild(menuList);
  document.body.appendChild(menu);
  return menu;
}