EdgeX Foundry is going to change the default message payload format in v4

[cloudxxx8]

What would you like to be added/modified:

If the source is EdgeX source or sink is EdgeX sink, the message envelope payload format will be different in v4.
We won't use base64 encoded for the normal JSON.

example from the original message:

{
  "ReceivedTopic":"",
  "CorrelationID":"14a42ea6-c394-41c3-8bcd-a29b9f5e6835",
  "ApiVersion":"v2",
  "RequestID":"e6e8a2f4-eb14-4649-9e2b-175247911369",
  "ErrorCode":0,
"Payload":"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",
  "ContentType":"application/json",
  "QueryParams":{}
}

propse to change to:

{
  "ReceivedTopic":"",
  "CorrelationID":"14a42ea6-c394-41c3-8bcd-a29b9f5e6835",
  "ApiVersion":"v3",
  "RequestID":"e6e8a2f4-eb14-4649-9e2b-175247911369",
  "ErrorCode":0,
"Payload":{"apiVersion":"v3","requestId":"e6e8a2f4-eb14-4649-9e2b-175247911369","statusCode":200,"deviceCoreCommand":{"deviceName":"Random-Boolean-Device","profileName":"Random-Boolean-Device","coreCommands":[{"name":"WriteBoolValue","set":true,"path":"/api/v2/device/name/Random-Boolean-Device/WriteBoolValue","url":"http://edgex-core-command:59882","parameters":[{"resourceName":"Bool","valueType":"Bool"},{"resourceName":"EnableRandomization_Bool","valueType":"Bool"}]},{"name":"WriteBoolArrayValue","set":true,"path":"/api/v2/device/name/Random-Boolean-Device/WriteBoolArrayValue","url":"http://edgex-core-command:59882","parameters":[{"resourceName":"BoolArray","valueType":"BoolArray"},{"resourceName":"EnableRandomization_BoolArray","valueType":"Bool"}]},{"name":"Bool","get":true,"set":true,"path":"/api/v2/device/name/Random-Boolean-Device/Bool","url":"http://edgex-core-command:59882","parameters":[{"resourceName":"Bool","valueType":"Bool"}]},{"name":"BoolArray","get":true,"set":true,"path":"/api/v2/device/name/Random-Boolean-Device/BoolArray","url":"http://edgex-core-command:59882","parameters":[{"resourceName":"BoolArray","valueType":"BoolArray"}]}]}},
  "ContentType":"application/json",
  "QueryParams":{}
}

Why is this needed:

Please see the issue description:
edgexfoundry/go-mod-messaging#381