Important: #108796 - Internal shortcut classes renamed to bookmark 

See forge#108796

Description 

As part of the centralized bookmark management feature, several internal classes related to backend shortcuts have been renamed to use "bookmark" terminology. These classes were marked as @internal and are not part of the public TYPO3 API. However, some extensions might have used them although they were internal.

The following classes have been renamed or replaced:

\TYPO3\CMS\Backend\Backend\Shortcut\ShortcutRepository
Removed and replaced by \TYPO3\CMS\Backend\Backend\Bookmark\BookmarkService and \TYPO3\CMS\Backend\Backend\Bookmark\BookmarkRepository
\TYPO3\CMS\Backend\Controller\ShortcutController
Renamed to \TYPO3\CMS\Backend\Controller\BookmarkController
\TYPO3\CMS\Backend\Backend\ToolbarItems\ShortcutToolbarItem
Renamed to \TYPO3\CMS\Backend\Backend\ToolbarItems\BookmarkToolbarItem

The JavaScript module @typo3/backend/toolbar/shortcut-menu has been removed and replaced by the new bookmark management modules in @typo3/backend/bookmark/.