route namespace

design notes for #850

I estimate completing the implementation will take half a day.


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UPDATE (from Adam): This took over a day to change it from design to implementation, including hours of pairing, but the estimate was for Jean-Paul alone and I'm slower. There are also a few TODOs with questions about how to continue.

Fixes #850 

I decided that `Deployer` will have a `volume_namespace` attribute for #737.  Since all components use the same namespace... this could still work (although I am not looking forward to yet another "default" to fix).

I wonder why `application.ports` is a collection of objects that aren't `Proxy` instances already.