Infer has_soma_location from part_of for neuron

[dosumis]

See obophenotype/cell-ontology#2246 (comment) for background and discussion.

is_neuron o 'part of' o 'is_anatomical_entity' -> 'has soma location'

Use local reflexivity pattern to define is_neuron & is_anatomical_entity:

ObjectProperty: is_neuron
Domain: neuron

Class: neuron
SubClassOf: is_neuron Self

[dosumis]

CC @cmungall @balhoff