Important: #78650 - TypoScriptService class moved from Extbase to Core ¶
See Issue #78650
The PHP class
has been moved to the core extension, as it has no direct link
to Extbase, and a lot of other system extensions are using the class.
The old class name is still registered as a class alias, so extensions can call the class via the Extbase PHP namespace in TYPO3 v8 without any downsides.