This commit introduces a new audit event atype: "clientMetadata". This event is emitted when metadata for a client connection is finalized during the first hello request. This new type of event may have two fields in "param":

• "localEndpoint" will contain the interface upon which the connection was established. It can be either a port and ip (
  Unknown macro: {ip}

  ) or a file path (

  Unknown macro: {unix}

  ).

• "clientMetadata" will contain the metadata provided by the client driver (if any) including application name. This currently has a schema like so:
  "clientMetadata" : {
  "application" :
  Unknown macro: { "name" }

  ,
  "driver" :

  Unknown macro: { "name" }

  ,
  "os" :

  Unknown macro: { "type" }

  }

This commit also introduces a new field "uuid" in every audit entry which can be used to uniquely identify a client connection. This uuid is also logged as part of LOGV2(22943) and LOGV2(22944).

Lastly, the "local" field in audit entries is to be considered deprecated in favor of the "param.localEndpoint" field in the "clientMetadata" event. We have no plans to remove the "local" field at this time, but we are reserving the right to do so if we need to reduce the size of audit logs in a future stable release.