Add a specific ImageRegionSplitter implementation :
- which generates tiles of 1 pixel height
- with the same tile width as the one computed with the meory estimator
- with a tile width aligned on the ShrinkFactor
Add a specific StreamingManager implementation which make use of the StreamingShrinkImageRegionSplitter
Make this specific StreamingManager the default implementation used by StreamingShrinkImageFilter

REFAC: add a StreamingManager class, rework the streaming management of StreamingImageVirtualFileWriter

- Add a StreamingManager class, integrating the PipelineMemoryPrintCalculator, and managing several streaming policies
 (stripped by specified number of lines, stripped by available memory, tiled by specified tile dimension, tiled by available memory)
- In tile mode, the class uses the new ImageRegionSquareTileSplitter, which generates square tiles
- Integrate the StreamingManager into the StreamingImageVirtualWriter as the only object responsible for streaming policy.
  The filter relies on this object to get the number of splits and iterate in the splits, without knowing the underlying implementation
- Add proper progress reporting in the StreamingImageVirtualWriter, by observing the progress events generated by the source object,
  to provide a continuous progress update instead of a tile by tile progress
- Make the necessary changes in the tests to account for new streaming parameters specifications

If the underlying filter sends a lot of ProgressEvent, the current watchers implementation triggered
a visualisation update at each ProgressEvent, thus reducing overall performance