Refactor console management

[briandealwis]

Following on #1248 and #2140:

@elharo: Why does DeployConsole extend MessageConsole? The latter is "@noextend This class is not intended to be subclassed by clients."

The current console management between DeployConsole, LocalAppEngineConsole, and their factories is a bit convoluted and should be simplified. Our subclasses are necessary to allow changing the name in response to state changes. We should be able to just use our own subclass of IOConsole.