Right now running `MongoDB: Connect` in the command prompt (cmd + shift + p) opens the overview page, which has buttons to open the connection form on it. We can make this flow more streamlined by folks by using the connection quick pick menu. This has an `add new connection` option which would open the overview page with the connection form. 

There's an existing `MongoDB: Change active connection` command. We can use this to replace the current connect command.