[BUGFIX] Fix usage of deprecated methods in FluidTemplateContentObject

StandaloneView now supports fallback paths.
The old setters are deprecated.
Use the plural method names.

Resolves: #63066
Releases: master
Change-Id: I6281c93047672e252735d99b8c76e5700efc2fed
Reviewed-on: http://review.typo3.org/34340
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Tested-by: Frans Saris <franssaris@gmail.com>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>