Write a client

[bkuczenski]

This is, strictly speaking, an upstream issue because we want a desktop antelope.py instance to be able to access the remote xdb server The main thing it needs to do is:

• replace CatalogQuery with a dedicated-endpoint query
• internalize https
• cache created entity refs (process refs already cache LCI; flow refs already cache CFs)

The thing that gets complicated is: we need to reform how queries are instantiated, to allow this non-CatalogQuery to be available to the user

[bkuczenski]

this is done in antelope_core