SKAMPI Alignment for environment management(integration/staging), CI/CD and MR workflow

In order to align MVP project (SKAMPI repository) with the rest of the component repositories with respect to developer experience, the CI/CD, environment management and repository needs to be refactored. The expected outcome is lesser developer headache when working in SKAMPI repository by more streamlined processes in the repository that reflects the common practice in other repositories. In addition, an introduction of a working integration and staging environments that will be deployed and accessed from the SKA HQ OPS room (and anywhere in the world) in a sense to ramp up release and staging environments for AA 0.5.

• SKAMPI testing is refactored so that different levels of testing follows the pipeline machinery, aligning the configuration and definition of the tests
• kubernetes pod creation for local tests (tests residing in skampi, integration/e2e tests) are scraped (if it's already the case, it's moved to the pipeline machinery). << This may mean refactoring in k8s-test target (or adding a new target)
• component tests are broken down into sequential jobs so that they are easy to develop and introduce by developers (the idea is developers should only need to change configuration (to enable/disable charts) when adding component tests to skampi)
• Staging environment is created and deployed using the charts in CAR in SDH&P Cluster(not in the repo!) << TBD: talk with Piers
  • Expose ports (IRIS support) and setup reverse proxy for SDH&P external access, configure OAuth2 integration (will require IT) - on jupiter
  • deploy nexus cache
• Runners and GitLab Agent is deployed to SDH&P cluster to support staging environment deployments
• attic folder is deleted
• CI/CD is aligned for all different configuration (mid/low) and environments (STFC Integration, PSI integration, staging envs etc.)
• Documentation is refactored to reflect the new changes (old documentation is removed! not archived!)

• Components tests are removed from SKAMPI
• `k8s-test-runner` target and ci template is added to Pipeline Machinery to run tests directly on the runner pod and used in SKAMPI:  https://gitlab.com/ska-telescope/ska-skampi/-/blob/master/.gitlab/ci/common.gitlab-ci.yml#L30 
• runners are deployed into operation sandbox environment and used by SDP pipelines (not SKAMPI)
• attic folder is deleted
• SKAMPI documentation regarding the pipelines are updated https://gitlab.com/ska-telescope/ska-skampi/-/blob/master/docs/src/pipelines.rst 

There are still some work to be done: i.e. release a new chart, use skampi in ops-sandbox which will be handled by parts of SP-2761