Reuse FlowProperty (name and synonyms) for other Flow properties (context, cas and unit)

[fjuniorr]

There is a lot of duplication between FlowProperty used for Flow.name and Flow.synonyms and the classes:

• Context
• CAS
• Unit

It makes sense to reduce duplication probably through inheritance.

[cmutel]

I think this is nice to have - there are other things more important for now. I looked through the linked examples, the overlap is there but not huge.