Breaking: #61822 - deprecated function getUniqueFields() removed 

See forge#61822

Description 

The function getUniqueFields() from \TYPO3\CMS\Core\DataHandling\DataHandler has been removed. The function is available in \TYPO3\CMS\Version\Hook\DataHandlerHook.

Impact 

Extensions that still use the function getUniqueFields() won't work.

Affected installations 

A TYPO3 instance is affected if a 3rd party extension uses the removed function.

Migration 

Replace all calls to \TYPO3\CMS\Core\DataHandling\DataHandler::getUniqueFields() with calls to \TYPO3\CMS\Version\Hook\DataHandlerHook::getUniqueFields()