e2e/loadbalancer: implement hairpin connection cases

Implementing the hairpin connection test cases, and exposing an issue on
NLB with internal scheme which fails when the client is trying
to access a service loadbalancer which is hosted in the same node.

The hairpin connection is caused by the client IP preservation attribute
is set to true (default), and the service does not provide an interface
to prevent the issue.

The e2e is expecting to pass to prevent permanent failures in CI, but it
is tracked by an issue #1160.

Author: mtulio