[TASK] Move arguments to initializeArguments() in PaddingVH in ext:fluid

[TASK] Move arguments to initializeArguments() in PaddingVH in ext:fluid

Move the argument registrations away from the render() method
to initializeArguments(), to prevent any errors with PHP7 and
subclassed ViewHelpers if/when render() method signatures change.
Change the UnitTest PaddingViewHelperTest with setArguments()

Resolves: #77061
Releases: master
Change-Id: Ib9c57d6e6927358c427c61ed1dd446cfe90ed8bd
Reviewed-on: https://review.typo3.org/48925
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Bamboo TYPO3com <info@typo3.com>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Susanne Moog <typo3@susannemoog.de>
Tested-by: Susanne Moog <typo3@susannemoog.de>