Allow the SeleniumBase Recorder to record actions inside iframes.

[mdmintz]

Allow the SeleniumBase Recorder to record actions inside iframes. This was previously a tricky thing to do, but I discovered a solution that gets the job done.

[mdmintz]

Based on https://stackoverflow.com/questions/2381336/detect-click-into-iframe-using-javascript, one can detect when someone clicked inside an iframe, even though you can't detect what was clicked. To get around the issue of detecting what was clicked, SeleniumBase can either navigate to the URL of the iframe (if there's an src attribute), or make the current page take on the content of the iframe otherwise.