Add Missing Event Function GURLGURL (JXA-equivalent of open location)

[stephancasas]

To handle custom URL schemes registered with lsregister, JXA applications should declare the function GURLGURL (as in "get URL"). The function should accept one argument — the prefixed URL as a string:

#!/usr/bin/env osascript -l JavaScript

function GURLGURL(url) {
  const App = Application.currentApplication();
  App.includeStandardAdditions = true;

  App.doShellScript(`echo ${url} > ~/Downloads/url-arg.txt`);
  return true;
}

This would be the equivalent of declaring on open location in a normal AppleScript document.

Cheers.