Generic ObservableObjects should be avoided when other classes exist

[ajnelson-nist]

example.py currently yields some graph nodes typed as uco-observable:ObservableObject without further subtyping.

More specific classes should be used when available. However, this might require a less manual maintenance method for aligning the Python class structure with the ontology.

[ajnelson-nist]

E.g., this:

CASE-Mapping-Python/example.py

Line 36 in 1cfd9b0

device_camera = uco.observable.ObservableObject()

should be replaced with:

device_camera = uco.observable.Device()