Add operation and field constants

- Add operationEvaluate, operationLookup, operationVerify constants
- Add fieldID constant for API responses
- Prepare for replacing telemetry operation strings

Author: haasonsaas

services/authz/server/server.go

@@ -49,6 +49,10 @@ const (
 	serviceNameMFA           = "mfa"
 	serviceNameInventory     = "inventory"
 	statusError              = "error"
+	operationEvaluate        = "evaluate"
+	operationLookup          = "lookup"
+	operationVerify          = "verify"
+	fieldID                  = "id"
 	errDecodeRequest         = "bad request"
 	errMissingMFAParams      = "missing MFA parameters"
 	errMethodNotAllowed      = "method not allowed"