[TASK] Remove unused RenderViewHelper

Releases: 6.1,6.2

Change-Id: Ic0efc4ec66c5e375ff89ccf2f47f6f18c5e03a46
Reviewed-on: https://review.typo3.org/25787
Reviewed-by: Nico de Haen
Tested-by: Nico de Haen