Implement kubectl helper integration tests

[pablochacin]

Description

Reimplements kubectl package e2e tests using TestContainers and move them to the package as integration tests

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works.
• I have run linter locally (make lint) and all checks pass.
• I have run tests locally (make test) and all tests pass.
• I have run relevant integration test locally (make integration-xxx for affected packages)
• I have run e2e test locally
• Any dependent changes have been merged and published in downstream modules
  

[codefromthecrypt]

drive by: just wanted to say I really like what you did. It is concise and readable and balances abstraction well!