[TASK] Deprecate extbase EmptyView

Extbase EmptyView is unused since its introduction in
4.5. Calling render() returns a html comment. It has
been substituted by NotFoundView within 4.5 development
already. NotFoundView is removed with a different
patch, too.

Resolves: #95005
Related: #95003
Releases: master
Change-Id: I8bbb4a641fa05fe34e2f7eabd7621ec3c0fe7bdd
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/70769


Tested-by: core-ci <typo3@b13.com>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>