Add new resource for Kubernetes API proxy (#279)

This adds a new resource which deploys a Kubernetes API server proxy
that can be used to access the API server without tokens through
Netbird.

Part of #274 

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## Summary by CodeRabbit

* **New Features**
* Added ClusterProxy custom resource for cluster API proxying
capabilities

* **Documentation**
  * Added ClusterProxy API reference documentation with schema details

* **Examples**
* Added example ClusterProxy configuration and RBAC setup for cluster
proxy targets

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.golangci.yml

@@ -57,6 +57,8 @@ linters:
           alias: metav1
         - pkg: k8s.io/api/core/v1
           alias: corev1
+        - pkg: k8s.io/api/rbac/v1
+          alias: rbacv1
         - pkg: k8s.io/api/apps/v1
           alias: appsv1
         - pkg: k8s.io/api/admission/v1
@@ -67,6 +69,8 @@ linters:
           alias: metav1ac
         - pkg: k8s.io/client-go/applyconfigurations/core/v1
           alias: corev1ac
+        - pkg: k8s.io/client-go/applyconfigurations/rbac/v1
+          alias: rbacv1ac
         - pkg: k8s.io/client-go/applyconfigurations/apps/v1
           alias: appsv1ac
         - pkg: k8s.io/client-go/applyconfigurations/policy/v1