Refactoring of blob detection

Refactoring of blob detection

• Implemented as a function instead of a class
• Added variable types to function arguments
• Combined the old detect and get_mask into a single function blob_detection that returns both the blobs and the binary mask
• Updated documentation example
• Updated example notebook docs/notebooks/blob_detection.ipynb

qim3d/processing/__init__.py

 from .local_thickness_ import local_thickness
 from .structure_tensor_ import structure_tensor
+from .blob_detection import blob_detection
 from .filters import *
-from .detection import *
 from .operations import *
 from .cc import get_3d_cc