Support changing namespace of kong addon builder

[randmonkey]

Is there an existing issue for this?

• I have searched the existing issues

Problem Statement

The current builder of Kong addon to deploy kong gateway does not support changing namespace to deploy kong gateway in another namespace, other than the default kong-system. This blocks Kong/kubernetes-ingress-controller#4431.

Proposed Solution

• Add a WithNamespace in kong.Builder to deploy Kong gateway in another namespace.

Additional information

No response

Acceptance Criteria

• Could specify namespace to deploy Kong in kong.Builder.