[BUGFIX] Make ToggleExtensionInstallationStateViewHelper PHP 7 compliant

[BUGFIX] Make ToggleExtensionInstallationStateViewHelper PHP 7 compliant

Match the declaration of the render function with the function
declaration of the base class.

In addition cleanup some code.

Resolves: #71304
Releases: master
Change-Id: I26527229ccf47928e954c412b4046d55c228e9de
Reviewed-on: https://review.typo3.org/45160
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Tested-by: Frans Saris <franssaris@gmail.com>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>