Add unit tests for KubernetesCluster, Tenant, ServiceInstance, and RegisterClusterHandler

- Implement tests for KubernetesCluster including registration, connectivity status, and error handling.
- Create tests for Tenant creation, member management, and status changes.
- Add tests for ServiceInstance provisioning and state management.
- Introduce RegisterClusterHandler tests to validate registration requests and error scenarios.
- Set up project files for new test projects with necessary dependencies.

src/EntKube.Web/Components/Account/PasskeyOperation.cs

@@ -0,0 +1,7 @@
+namespace EntKube.Web.Components.Account;
+
+public enum PasskeyOperation
+{
+    Create = 0,
+    Request = 1,
+}