Consider adopting a full sans I/O approach

[prkumar]

On gitter, @asmodehn shared their questions/concerns regarding how uplink manages I/O and pointed us towards the sans I/O approach. In my response, I noted that we currently do abstract a lot of the I/O work behind uplink.clients.io, but I also think there may be room for improvement here: we should consider incorporating the learnings and methodology of the sans I/O approach into the design of our own abstractions.

This effort seems pertinent to our Common Client Interface project.