debugZoneErrorsAreFatal property

Whether debugCheckZone should throw (true) or just report the error (false).

Setting this to true makes it easier to catch cases where the zones are misconfigured, by allowing debuggers to stop at the point of error.

Currently this defaults to false, to avoid suddenly breaking applications that are affected by this check but appear to be working today. Applications are encouraged to resolve any issues that cause the debugCheckZone message to appear, as even if they appear to be working today, they are likely to be hiding hard-to-find bugs, and are more brittle (likely to collect bugs in the future).

To silence the message displayed by debugCheckZone, ensure that the same zone is used when calling ensureInitialized() as when calling the framework in any other context (e.g. via runApp).