Submit the protocol_version as part of submit_measurement

[hellais]

The submission handler should handle also invalid credentials and protocols, processing the measurements, but signaling to the caller that it's going to get marked as not verified.

See: https://github.com/ooni/userauth/pull/32/changes

[hellais]

This is how the client request should look like now:

class SubmitMeasurementRequest(BaseModel):
    format: str
    content: Dict[str, Any]
    # -- < Anonymous Credentials > ----------------------
    # not post quantum, in the future we might want to use a hashed key for storage
    nym: Optional[str]
    zkp_request: Optional[str]
    manifest_version: Optional[str]
    protocol_version: Optional[str]

If the protocol_version is not supported, we should mark the measurement as not valid and return to the called status 200, but with inside a payload that contains these additional keys:

{
  "measurement_uid": "XXXX",
  "error": "invalid_protocol_version",
  "is_verified": false,
  "submit_response": null,
  "protocol_version": "x.x.x"
}

We can always return the protocol_version and make the error string nullable. The client should return the error and protocol_version to the caller so they can make use of them.

[DecFox]

This has been completed in ooni/ooniprobe-rs#11