[WIP] Validate open ports

[tnozicka]

Description of your changes: This PR adds an e2e test that validates open ports for our ScyllaDB Pod in "default" configuration.

The aim of this test is to:

• Discover what ports are open
• Serve as a driving point to migrate to secure ports / services
• Enforce that only listed ports are open

Which issue is resolved by this Pull Request: Resolves #1760

Requires

• [ ] https://github.com/scylladb/scylla-jmx/issues/236

[scylla-operator-bot[bot]]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tnozicka

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[scylla-operator-bot[bot]]

@tnozicka: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/e2e-gke-parallel-clusterip	067adc2cf1b8da1ec08ab26f80c155e3fbafb779	link	true	/test e2e-gke-parallel-clusterip
ci/prow/e2e-gke-parallel	067adc2cf1b8da1ec08ab26f80c155e3fbafb779	link	true	/test e2e-gke-parallel
ci/prow/e2e-gke-release-script-latest	067adc2cf1b8da1ec08ab26f80c155e3fbafb779	link	true	/test e2e-gke-release-script-latest

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