[FEATURE] Create an UnlessViewHelper as opposite to the IfViewHelper (Revision 6)

This changeSet adds a new UnlessViewHelper which acts excactly
like the IfViewHelper apart from the Negation of the condition.

Main reason for this new ViewHelper is to have a quicker way to
handle an if->else usecase like::

	<f:for each="{emptyQuery}" as="object">…</f:for>
	<f:unless condition="{emptyQuery}">No Objects found</f:unless>

Resolves: #52640
Releases: master
Change-Id: I933f48ae63f81e0119d74afb875463a24067cbd7
Revision-Id: f523650dac5d007022ff7c6ca335fdd507b7150b