Revert "[FEATURE] Support @Flow\Inject annotations in Extbase"

This reverts commit 09bc492925713036cef679c92ffc28eda941605c

We should not support this annotation in extbase, because it
has no benefit and breaks with the annotation concept in
Flow. "Flow" is only an alias for "TYPO3\Flow\Annotations" in
Flow and needs to be registered by "use TYPO3\Flow\Annotations as Flow".

Change-Id: Ic0ecdc58754c176b1140db463c2405cb47bf9933
Reviewed-on: https://review.typo3.org/21997
Reviewed-by: Marc Bastian Heinrichs
Tested-by: Marc Bastian Heinrichs