Add an additional submit technique before form.submit()

[luckyrat]

This might increase the success rate of form submissions by triggering the submit event on the webpage.

const button = document.createElement('input');
button.type = 'submit';
form.append(button);
button.click();
button.remove();

This was described as a workaround for the challenges that led to the recent introduction of form.requestSubmit() but in our case we already fake a user click on any button that we can correctly identify. When we can't find a button to click, this workaround might prove more reliable than the good old form.submit() fallback.

See: https://github.com/whatwg/html/issues/4187