Add support for private gateway (#154)

This change adds support for TCPRoutes when using a private gateway
class. This is similar to annotating services today. It also moves the
gateway classes to the Helm chart as it makes things a lot simpler for
the end user as they no longer have to define them.

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

examples/gateway-api/values.yaml

@@ -0,0 +1,14 @@
+gatewayAPI:
+  enabled: true
+
+webhook:
+  enableCertManager: false
+
+netbirdAPI:
+  keyFromSecret:
+    name: "netbird-mgmt-api-key"
+    key: "NB_API_KEY"
+
+operator:
+  image:
+    tag: dev