Refactor tests for processing and adapt it to new library structure, plus fix...

Refactor tests for processing and adapt it to new library structure, plus fix unit tests for processing

qim3d/operations/_common_operations_methods.py

 import numpy as np
 import qim3d.filters as filters
-from qim3d.utils._logger import log
+from qim3d.utils import log
 
 __all__ = ["remove_background", "fade_mask", "overlay_rgb_images"]