BUG: Checks added for slice view annotations

Slice view annotations generated many pages of error messages in case of slicelets, where custom layout managers are used

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23782 3bd1e089-480b-0410-8dfb-8563597acbee
STYLE: Fixed typo in DataProbe member variable name

git-svn-id: http://svn.slicer.org/Slicer4/trunk@23783 3bd1e089-480b-0410-8dfb-8563597acbee