Breaking: #81735 - Get rid of sysext:sv

See Issue #81735

Description

The AuthenticationService has been moved into system extensios core. Class aliases are in place and will be removed with TYPO3 v10.

Impact

The namespace of the classes AbstractAuthenticationService and AuthenticationService changed from \TYPO3\CMS\Sv to \TYPO3\CMS\Core\Authentication.

Affected Installations

All instances, that use or extend the mentioned classes.

Migration

Use the new namespaces as mentioned above.