Added karma notifications

[przemyslaw-zan]

Feature (tests): Added karma notification for when the tests are completed. Notification can be enabled with -n/--notify CLI option. Its enabled by default when running all tests, without the -f/--files option. Closes ckeditor/ckeditor5#13736.

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Additional information

(This happened on Windows 10)

I've encountered a small issue where the first attempt to use the notifier did not work, and only following attempts worked successfully. It happened when I've started with hard-coded value: reporters: [ 'progress', 'notify' ], so it might not be an issue.

Reviewers should make sure that the current setup works on first try.

[coveralls]

Coverage: 87.903% (-0.3%) from 88.214% when pulling 11edec3 on ck/13736 into a641d0f on master.

[martnpaneq]

Works fine on mac :)

The only issue I had was that I rejected the notification on the first run, and I could no longer see any notifiactions.
In this case resetting notification settings for terminal fixed it for me:

[arkflpc]

Works on Linux under KDE.

[psmyrek]

Notification works in Windows 11:

The not cool thing is that it adds a shortcut in the Start menu...

Could you please check if this could be prevented somehow?

[psmyrek]

Possible workaround:

const notifier = require( 'node-notifier' );
const isWindowsNotifier = notifier.Notification === notifier.WindowsToaster;

if ( isWindowsNotifier ) {
	const originalNotify = notifier.notify;

	notifier._notify = notifierOptions => originalNotify( {
		...notifierOptions,
		appID: 'karma-notify-reporter'
	} );
}

[przemyslaw-zan]

☝️ To avoid workarounds, we've decided to implement a custom notifier instead.

[przemyslaw-zan]

Right now notifications use default icon. Do we want to use custom icons, and if so, where do we take them from? Should we have different icons for success and failure, or perhaps simple CKE5 logo for all notifications would be sufficient?

[pomek]

LGTM.