Idea: possibly avoid setTimeout and waitForScriptToLoad

[0biWanKenobi]

So while looking at the code, I noticed that after the api.js script has been loaded, a 25ms looping setTimeout starts, waiting for the grecaptcha instance to be available. Now, in most cases the instance is already available and the timeout never starts, so that's good. But I was wondering if we could skip all of that logic alltogether, and rely on the onload callback that we can provide to ReCaptcha.

Code snippet below, I'm testing it with patch-package and it seems to work flawlessly. Wdyt, worth a PR?

// inside ReCaptchaLoader.prototype.loadScript 
// [...]

if(renderParameters.onload) {
  renderParameters.onload = undefined;
}

var parametersQuery = this.buildQueryString(renderParameters);
scriptElement.src = scriptBase + '?render=explicit&onload=onRecaptchaLoad' + parametersQuery;


var _onRecaptchaLoad = (callback, useEnterprise) => {
  if (useEnterprise) {
    window.grecaptcha.enterprise.ready(function () {
        callback();
    });
  }
  else {
      window.grecaptcha.ready(function () {
          callback();
      });
  }
}

return new Promise(function (resolve, reject) {
    const onSuccess = () => {
      resolve(scriptElement)
      window.onRecaptchaLoad = undefined
    }
    window.onRecaptchaLoad = () => {
      _onRecaptchaLoad(onSuccess, useEnterprise)
    }
    scriptElement.onerror = function (error) {
        ReCaptchaLoader.setLoadingState(ELoadingState.NOT_LOADED);
        reject(error);
        window.onRecaptchaLoad = undefined
    };
    document.head.appendChild(scriptElement);
});