Add Authorization Server to RegisterEndpointEvent

[stevenvegt]

In order for the client side to retrieve the oauth access token, for every resource server as defined by the endpoint, we need to know the endpoint of the authorization server.

Event can look like this:

{
  "type": "RegisterEndpointEvent",
  "payload": {
    "organization": "urn:oid:2.16.840.1.113883.2.4.6.1:12345678",
    "endpointType": "urn:oid:1.3.6.1.4.1.54851.1:nuts-oauth-authentication-server",
    "identifier": "b005875b-2bd5-4a1b-b9eb-92622942dcf4",
    "status": "active",
    "version": "0.1.0",
    "URL": "http://127.0.0.1:21234",
    "authorizationServerURL": "https://nuts.examplecare.org/oauth"
  }
}

[reinkrul]

I'd rather add a property bag instead of extending an event with a dynamic set of unknown properties (since each endpoint type can have a different set of extra properties) since that makes deserialization less ambiguous (separate the known from the unknown). Something like this:

{
  "type": "RegisterEndpointEvent",
  "payload": {
    "organization": "urn:oid:2.16.840.1.113883.2.4.6.1:12345678",
    "endpointType": "urn:oid:1.3.6.1.4.1.54851.1:nuts-oauth-authentication-server",
    "identifier": "b005875b-2bd5-4a1b-b9eb-92622942dcf4",
    "status": "active",
    "version": "0.1.0",
    "URL": "http://127.0.0.1:21234",
    "properties": {
      "authorizationServerURL": "https://nuts.examplecare.org/oauth"
    }
  }
}