Report exceptions for async script executions to webdriver (#27041)

Improving the accuracy of the async script execution for our webdriver
implementation allows us to run many more webdriver tests without
timeouts, which should help with
https://github.com/web-platform-tests/wpt/issues/24257.

Specification:
* https://w3c.github.io/webdriver/#dfn-clone-an-object
* https://w3c.github.io/webdriver/#execute-async-script

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #27036 and fix #27035 and fix #27031.
- [x] There are tests for these changes (but we don't run them in CI
yet)

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

components/script_bindings/webidls/Window.webidl

@@ -148,6 +148,7 @@ partial interface Window {
 partial interface Window {
   // Shouldn't be public, but just to make things work for now
   undefined webdriverCallback(optional any result);
+  undefined webdriverException(optional any result);
   undefined webdriverTimeout();
 };