message: Correct python 3 bytes decode for module name
  Summary:
  Python3 protobuf returns a byte array instead of a string for string fields,
  which then needs to be decoded into a string.
  Test Plan: buildbot python3
  Reviewers: georgep
diff: @@ -88,9 +88,9 @@ def extract_all_strings_from_event_trace(events):
  time.strftime('%F %T %z', time.localtime(evt.timestamp)) + ": "
  if evt.type == IpuTraceEvent.COMPILE_BEGIN:
  - evt_str = "Compile begin: " + evt.module_name + "\n"
  + evt_str = "Compile begin: " + evt.module_name.decode('utf-8') + "\n"
  elif evt.type == IpuTraceEvent.COMPILE_END:
  - evt_str = "Compile end: " + evt.module_name + "\n" + \
  + evt_str = "Compile end: " + evt.module_name.decode('utf-8') + "\n" + \
  "Duration: " + str(evt.data_int) + " us\n" + \
  evt.data_str.decode('utf-8')
  elif evt.type == IpuTraceEvent.HOST_TO_DEVICE_TRANSFER:
  @@ -100,7 +100,7 @@ def extract_all_strings_from_event_trace(events):
  evt_str = "Device->Host\nHandle = " + evt.data_str.decode('utf-8') + "\n"
  #"Bytes = " + str(evt.data_int)
  elif evt.type == IpuTraceEvent.LOAD_ENGINE:
  - evt_str = "Load engine: " + evt.module_name + "\n"
  + evt_str = "Load engine: " + evt.module_name.decode('utf-8') + "\n"
  elif evt.type == IpuTraceEvent.EXECUTE:
  evt_str = "Execute\n" + evt.data_str.decode('utf-8')
  else:
  