Postgres - List tables under schemas in Details-View

[nikisix]

We have databases with literally thousands of tables and need tables to be listed under their schemas in the details view.

[DSpeckhals]

A lot of the back-end work for this was already done in #55. It's just a matter of allowing the details view to drill down to lists of tables via schema. I might have a chance to work on this within the next few weeks; I have a similar interest in this functionality.

[lukemurray]

Thanks @DSpeckhals that would be awesome!