fix: Status now serializes to json

[ericswanson-dfinity]

Description

Status now serializes to json everything in the values map, without the enum types

Part of https://dfinity.atlassian.net/browse/SDK-1457

Prior, serializing to json looked like this:

{
  "impl_hash": "a380266e4b6977b7cce447aa5f784efdba0bb45820d51f39b9e7908f7fbb1aa1",
  "replica_health_status": "healthy",
  "root_key": [ 48, 129, 130 ],
  "values": {
    "certified_height": {
      "Integer": 948674
    },
    "ic_api_version": {
      "String": "0.18.0"
    },
    "impl_hash": {
      "String": "a380266e4b6977b7cce447aa5f784efdba0bb45820d51f39b9e7908f7fbb1aa1"
    },
    "impl_version": {
      "String": "0.9.0"
    },
    "replica_health_status": {
      "String": "healthy"
    },
    "root_key": {
      "Bytes": [
        48,
        129,
        130
      ]
    }
  }
}

How Has This Been Tested?

Changed the test to build the Status from cbor, in order to populate the values the way that actually happens. Also tested locally with dfx ping:

$ dfx ping
{"certified_height":953309,"ic_api_version":"0.18.0","impl_hash":"a380266e4b6977b7cce447aa5f784efdba0bb45820d51f39b9e7908f7fbb1aa1","impl_version":"0.9.0","replica_health_status":"healthy","root_key":[48,129,130,48,29,6,13,43,6,1,4,1,130,220,124,5,3,1,2,1,6,12,43,6,1,4,1,130,220,124,5,3,2,1,3,97,0,141,112,44,49,204,10,52,103,112,50,213,52,220,171,58,218,10,234,157,59,85,7,80,99,161,109,225,44,206,32,66,199,182,184,50,240,80,243,131,149,39,55,219,247,20,71,75,63,16,9,217,12,111,97,242,112,231,229,216,169,214,145,220,61,185,28,221,211,199,38,126,171,26,207,140,210,43,188,187,142,140,38,131,73,28,195,49,117,148,138,203,72,51,45,93,5]}

Checklist:

• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.
• I have made corresponding changes to the documentation.

[lwshang]

The original "bug report" was that dfx ping didn't print out valid JSON. The reason is that we print the Status directly without specifying a serializing format, i.e. JSON. Then the Display impl was used.

The JSON text in the description above was indeed valid JSON and can be parsed by standard JSON tools. So I don't think it is necessary to make this custom serializer for Status.

And since the /api/v2/status endpoint returns freeform CBOR data, the types of each field is important and should be included in the serialization.

---

Another thing I want to point out is which fields should be pre-defined in Status.
The interface-spec only mentions root_key. Any other fields are "additional implementation-specific fields". IMO, we should remove impl_version and replica_health_status field in Status.

---

And there is indeed a problem in the serialization that the pre-defined fields like root_key are also included in the CBOR value map which is certainly redundant.