ENH: incorporate metadata from EPANET file in PyPES model

[fletchapin]

Use Case

There is some metadata in EPANET files, such as pipe length or valve diameter, that is not saved when converting to a PyPES model.

Solution

Any metadata fields in the EPANET file that are supported by PyPES (e.g., diameter) should be saved in the PyPES model to avoid information loss.

Alternatives

A user could manually add the relevant metadata to the JSON file after conversion, but this is a painstaking process.