Do not return empty requested region in case StreamingWarpImageFilter

Summary

Do not return empty requested region in case StreamingWarpImageFilter legitimately asks for a requested region outside of input largest possible region, since it can mess with upstream filters that will throw InvalidRequestedRegionException because ImageRegion::Crop() can not crop empty regions and thus returns false.

Copyright

The copyright owner is CNES and has signed the ORFEO ToolBox Contributor License Agreement.

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