Feature: #97787 - Enum for severities introduced

See forge#97787


The PHP enum \TYPO3\CMS\Core\Type\ContextualFeedbackSeverity has been introduced, allowing streamlined usage of severities across the codebase. At the time of writing, this affects flash messages and status reports used in EXT:reports.


The enum cases in \TYPO3\CMS\Core\Type\ContextualFeedbackSeverity are meant to be a drop-in replacement for the severity constants of \TYPO3\CMS\Core\Messaging\FlashMessage and \TYPO3\CMS\Reports\Status.


Example of using the enum in a flash message:

$flashMessage = GeneralUtility::makeInstance(
    'Flash message text',
    'This is fine',

Example of using the enum in a status report:

$statusReport = GeneralUtility::makeInstance(
    'Not all lemmings were saved!',