The dbschema file should just show as a "disconnected" or "offline" jdbc
connection in the ui instead of a separate file and concept.

Here's a related conversation with Pavel:
>>     -I am not sure how useful it is to expose a JPA user to concept of
.dbschema. In my opinion, we should
>>      remove "Use a captured dbschema" from the wizard

>
> I think that it is useful to have the notion of captured DB schema. First, for
caching for better performance - AFAICT it shows even for a small size DB and
second, for offline work (when the DB is not available). Maybe the UI can be
improved in future. IMO we do not need to explicitly show .dbschema files, it
should be more in terms of "this is the DB that you are working with in this
project, the schema is either live - when you're connected - or offline - when
not connected."