"Change Database" should allow connecting to a server

[eben-roux]

It would be very handy if one could click on the "Change Database" button without first having to click the "Connect" button.

Currently one has to first click "Connect", wait for the connection, and then click the "Change Database" button to select the database.

When clicking "Change Database" without an active connection the connection dropdown should open followed by the database selection dropdown if a connection could be established.