runner: Add a socket comms decoder

When debugging, being able to read what is sent via socket comms is
very useful.

Signed-off-by: Petri Latvala <petri.latvala@intel.com>
Cc: Arkadiusz Hiler <arek@hiler.eu>
Acked-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>