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.Client/Pages/Auth.razor

@@ -0,0 +1,13 @@
+@page "/auth"
+
+@using Microsoft.AspNetCore.Authorization
+
+@attribute [Authorize]
+
+<PageTitle>Auth</PageTitle>
+
+<h1>You are authenticated</h1>
+
+<AuthorizeView>
+    Hello @context.User.Identity?.Name!
+</AuthorizeView>