Beam splitting off-axis zone plate analysis

This adds the beam splitting off-axis zone plate analysis code to the toolbox:

• determination of correction parameters are shown in a notebook documentation
• correction parameters and parameters used in their determination are all saved in one single JSON file for reproducibility
• analysis of actual data using these correction parameters is shown in a second notebook documentation

src/toolbox_scs/routines/__init__.py

 from .XAS import *
+from .boz import *
 
 # Module name is the same as a child function, we use alias to avoid conflict
 import toolbox_scs.routines.knife_edge as knife_edge_module
@@ -7,4 +8,5 @@ from .knife_edge import *
 __all__ = (
     knife_edge_module.__all__
     + XAS.__all__
+    + boz.__all__
 )