Add ability to subscribe/unsubscribe to streaming
telemetry updates. This may be more performant than
polling in some circumstances, and appears necessary
for good performance of autoflow tabular views,
WTD-614.
Bring in initial state for the platform/telemetry
bundle, which provides general-purpose telemetry
conventions and infrastructure to support creating
domain objects which expose telemetry data.
WTD-575.
