Support for deep tracing in k8s/Istio setup

[mik047]

Is your feature request related to a problem? Please describe.
We are trying Istio in our FHIO setup to (among other things) visualise requests flowing through different FHIO components.
To do so, it will need trace context propagation to be added in each FHIO component.

Describe the solution you'd like
Changes in Edge, Dacha and MR component so that it can send relevant http headers related to deep tracing (like span id) etc. while talking to its respective downstream dependencies.

Describe alternatives you've considered
None!

Additional context
Not required, I assume!

[rvowles]

Hiya @mik047 - this is in the current dockerhub 1.7.2-RC image