Implement a GaussianBlur in the readers during tile stitching.

[AjeyPaiK]

Is your feature request related to a problem? Please describe.
My segmentation outputs currently contain tiling artefacts. Even though StitchingMode.AVERAGE and StitchingMode.CROP have been implemented, StitchingMode.GAUSSIANBLUR is a desirable feature for ahcore.

Describe the solution you'd like
Define an additional member in the StitchingMode and implement a gaussian smoothing on the overlap region between two tiles.

Describe alternatives you've considered
N/A

Additional context
N/A.

[AjeyPaiK]

I will first implment a StitchingMode.AVERAGE. Then, I will progress to implementing a gaussian blurring on each tile before stitched image is generated.