Add tests similar to regular bilateral filter

[dzenanz]

Those can be found in the main repo, e.g.:
https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Filtering/ImageFeature/test/itkBilateralImageFilterTest3.cxx

[phcerdan]

I added the original tests of the Insight Journal submission also handling the cake_easy.png image in 15d8814