[nonblocking] aromaticity_model doesn't propagate

[jaclark5]

Describe the bug
The documentation specifies the inputs of Topology.chemical_environment_matches specifies that the aromatic_model can be set, but this value isn't used in the code.

Suggested Solution
Pass aromaticity_model and propagate through to the toolkit methods find_smarts_matches in the method FrozenMolecule.chemical_environment_matches()

[j-wags]

Oh wow, good catch. This would also require adding the argument to FrozenMolecule.chemical_environment_matches. Unexpected and bad things happen to downstream packages when we fiddle around with base classes like that so this I'd like to hold this until we have another API breaking release planned.

In the meantime we could guard against this by raising an error if anything except "MDL" is provided.

[mattwthompson]

#453