Add network egress resource (#357)

This change adds a new import resource which enables exposing Netbird
resources as Kubernetes services. This remove the need to add sidecars
to every pod.

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added a new `NetworkEgress` custom resource (`netbird.io/v1alpha1`)
with CRD, schema validation, and status/conditions.
* Extended controller functionality to create egress services and
translate egress rules into import `EndpointSlice` resources; egress
pods now include a kube-egress-forwarder sidecar.
* **Bug Fixes**
* Added missing deep-copy and declarative apply support for the new
`NetworkEgress` API types.
* **Documentation**
* Updated README/API reference and added example manifests for
`NetworkEgress` (including IP/FQDN target usage).
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Signed-off-by: Philip Laine <philip.laine@gmail.com>

cmd/main.go

@@ -312,6 +312,19 @@ func main() {
 			setupLog.Error(err, "Failed to create controller", "controller", "NetworkResource")
 			os.Exit(1)
 		}
+		if err := (&controller.NetworkEgressReconciler{
+			Client:  mgr.GetClient(),
+			Netbird: nbClient,
+		}).SetupWithManager(mgr); err != nil {
+			setupLog.Error(err, "Failed to create controller", "controller", "NetworkEgress")
+			os.Exit(1)
+		}
+		if err := (&controller.ForwarderServiceReconciler{
+			Client: mgr.GetClient(),
+		}).SetupWithManager(mgr); err != nil {
+			setupLog.Error(err, "Failed to create controller", "controller", "ForwarderService")
+			os.Exit(1)
+		}
 		if err := (&controller.ClusterProxyReconciler{
 			Client:        mgr.GetClient(),
 			ApiKey:        netbirdAPIKey,