Important: #82229 - Fluid implementation of CmsVariableProvider removed

See forge#82229

Description

The PHP class within EXT:fluid named CmsVariableProvider was removed. The custom functionality is available in its parent class \TYPO3Fluid\Fluid\Core\Variables\StandardVariableProvider from Fluid standalone can be implemented directly.

Instantiating the removed class will still work through the functionality of class aliases in PHP, however, using the parent class is encouraged.