The legacy M.core.event.FORM_ERROR event has been replaced with a new
core_form/events::formError native DOM event.
The new event can be listened to at any point in the DOM using the
following syntax:
```
import {eventTypes} from 'core_form/events';
document.addEventListener(eventTypes.formError, handler);
```
A backward-compatabibility layer is included to ensure that any legacy
YUI event listener is still called with the same arguments.
This legacy bridges will be removed after Moodle 4.3.
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