Remove circular dependency in Kubernetes e2e tests

[pablochacin]

Currently, the Kubernetes helper package's tests use to some extend helper functions provided by that same package for the test setup, creating a kind of circular dependency between the tests and the package.

A better alternative would be to use other tools for test setup and for checking test conditions.

One possibility would be to run the tests as pods in the cluster using scripts and CLI tools such as kubectl. In this way the tests would be an automation of actions an operator could do.

One open question would be how to check the results of the test from the Job execution.