fix: show checkmark for checked menu item

[web-padawan]

Description

Fixes #2985 which was introduced by #2879 (adding checkmark part). Also added a visual test.

Type of change

• Bugfix

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[sissbruecker]

Can confirm that context menu has been fixed. However it seems the same issue also applies to menu bar, see this example for reference: https://vaadin.com/docs/latest/ds/components/menu-bar/#checkable-menu-items

[web-padawan]

@sissbruecker Note that vaadin-menu-bar uses the vaadin-context-menu-item internally:

web-components/packages/menu-bar/src/vaadin-menu-bar-buttons-mixin.js

Lines 268 to 273 in b4a9cea

	if (isElement && itemComponent.localName === 'vaadin-context-menu-item') {
	component = itemComponent;
	} else {
	component = document.createElement('vaadin-context-menu-item');
	component.appendChild(isElement ? itemComponent : document.createElement(itemComponent));
	}

[vaadin-bot]

This ticket/PR has been released with platform 22.0.0.beta2 and is also targeting the upcoming stable 22.0.0 version.