SBOL 2-3 Converter - Handle order in Locations

[PrashantVaidyanathan]

SBOL 2 doesn't have a way to store order in Location.

We need a way to store this information in SBOL 2 and have a helper function in the converter that can resolve this while converting form SBOL2 to SBOL3.

[jakebeal]

This can be implemented via a "backport" property, like we do for namespace.