[TIMOB-27528] iOS: uncaught exceptions in event listeners don't show error modal

If code throws an uncaught exception in a "new" obj-c based proxy inside of an event listener (possibly also a timer), it behaves differently than when an "old style" C-API proxy does so. In old style proxies, we had a global uncaught exception handler that popped the error modal dialog (and possibly also linked to the crash reporting module?). With new style proxies the exception basically gets propagated up and if the user JS code doesn't handle it via try/catch it can cause a crash. We had tried to handle this in an incorrect way that had to be rolled back here: https://github.com/appcelerator/titanium_mobile/pull/10862