Decommission embedded ingress

[abaguas]

Since #1557 (released on v0.13.0) k8gb can reference ingress resources via labels. This functionality provides the same features as embedded ingress configuration and is easier to maintain since the GSLB CRD does not depend on external CRDs. It also makes it easier to adopt k8gb since no ingress changes are required.

By decommissioning embedded ingresses the code base will be reduced, as well as the runtime of the tests, without any loss of functionality.

Plan of action:

• Update documentation to use referenced instead of embedded ingress resources
• Update k8gb-lite (annotation based) capability to create a GSLB with a referenced ingress instead of a GSLB with an embedded ingress. In version 1.0 both versions will be supported and a warning will be displayed. In version 1.1 the embedded option will be decommissioned.
• Remove embedded ingress from the CRD and codebase