Function defaultErrorHandler

defaultErrorHandler(): {
hide: () => void;
show: (ex: string | Error | Event) => void;
}
Creates an error handler to show errors on-screen. This is useful when testing on mobile devices that lack access to the console.
```
const e = defaultErrorHandler();
```
Manual control:
```
const e = defaultErrorHandler();
e.show(someError);
e.hide();
```
Returns { hide: () => void; show: (ex: string | Error | Event) => void }