Breaking: #69561 - Replace sprite icons with IconFactory in ContextMenu

See Issue #69561

Description

SpriteIcon and standalone image support have been replaced with IconFactory in the context menu. All menu icons now need to be registered through the IconRegistry.

Impact

The UserTsConfig options for items icon and spriteIcon have no effect anymore, and will deliver a blank placeholder image if iconName is not set.

Affected Installations

All installations that add or modify items in the ContextMenu.

Migration

Register the icon through the IconRegistry and set the iconName in the item configuration.

// Register Icon
$iconRegistry = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Core\Imaging\IconRegistry::class);
$iconRegistry->registerIcon(
        'contextmenu-example',
        \TYPO3\CMS\Core\Imaging\IconProvider\SvgIconProvider::class,
        array(
                'source' => 'EXT:example/Resources/Public/Icons/contextmenu-example.svg'
        ))
);

options.contextMenu.table {
        virtual_root.items {
                9999 = ITEM
                9999 {
                        name = contextmenuExample
                        label = LLL:EXT:example/Resources/Private/Language/locallang.xlf:contextmenu-example
                        iconName = contextmenu-example
                        callbackAction = exampleCallback
                }
        }
}