CefFrame evaluateJavascript

[DatL4g]

Is your feature request related to a problem? Please describe.
There is currently no way to execute some javascript and get the value back.

For example we wanna execute this script

(function() {
	const wantedA = document.getElementById("link");
	return wantedA.getAttribute("href");
})();

And get the String of the elements href back in Java.

Describe the solution you'd like
This is already implemented in CefSharp like this:

https://github.com/cefsharp/CefSharp/blob/2e2b53f8a1a3ee4839c7d1d18be8fa8b0269139f/CefSharp/IFrame.cs#L129

[magreenblatt]

See chromiumembedded/cef#3631 (and result callback to ExecuteJavaScript)