Postional vs keyword arg to NoStratigraphyError

[amoodie]

AI says where we pass obj to AttributeError as a positional argument, but that's not the usage for that. instead should be __init__(message, obj=obj)

sandplover/sandplover/utils.py

Line 68 in 34ddac0

super().__init__(message, obj)

Originally posted by @ericbarefoot in #250 (review)

[henriquejsza]

I can take this. I’ll pass obj as the AttributeError keyword argument and add a focused regression test for the exception metadata.