Authn: Add function to resolve identity from org and namespace id (#84555)

* Add function to get the namespaced id

* Add function to resolve an identity through authn.Service from org and namespace id

* Switch to resolve identity for re-authenticate in another org

pkg/services/authn/identity.go

@@ -87,6 +87,18 @@ type Identity struct {
 	IDToken string
 }
 
+func (i *Identity) GetID() string {
+	return i.ID
+}
+
+func (i *Identity) GetNamespacedID() (namespace string, identifier string) {
+	split := strings.Split(i.GetID(), ":")
+	if len(split) != 2 {
+		return "", ""
+	}
+	return split[0], split[1]
+}
+
 func (i *Identity) GetAuthenticatedBy() string {
 	return i.AuthenticatedBy
 }
@@ -122,16 +134,6 @@ func (i *Identity) GetLogin() string {
 	return i.Login
 }
 
-func (i *Identity) GetNamespacedID() (namespace string, identifier string) {
-	split := strings.Split(i.ID, ":")
-
-	if len(split) != 2 {
-		return "", ""
-	}
-
-	return split[0], split[1]
-}
-
 // GetOrgID implements identity.Requester.
 func (i *Identity) GetOrgID() int64 {
 	return i.OrgID