Fixes accidentally deleted serviceaccount and rolebinding objects

[soenkeliebau]

Description

Currently it is possible that servieAccount and roleBinding objects accidentally get deleted if multiple clusters of the same type (airflow, zookeeper, ...) get deployed to the same namespace and one of them gets deleted.

The issue is, that we don't name the serviceaccount and rolebinding objects after the clustername, but they are named the same for all cluster, so bacially just "airflow-rolebinding" and "airflow-serviceaccount" across the board.
When you new deploy two airflows into the same namespace and delete the wrong one of them again (the wrong one being the last that was deployed) then the rolebinding and serviceaccount are gone as well and the other cluster stops working as well.

Reason for "the last one" being the one that kills it is, because the ownerreferences of the rolebinding and serviceaccount point at this and the delete gets propagated to these two objects that are still needed by the other clusters.

This PR fixes how the names are built for the serviceAccount and roleBinding objects are created so that they are unique for each cluster.

fixes stackabletech/issues#675

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
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# Author
- [ ] Changes are OpenShift compatible
- [ ] CRD changes approved
- [ ] Integration tests passed (for non trivial changes)

# Reviewer
- [x] Code contains useful comments
- [x] (Integration-)Test cases added
- [x] Changelog updated
- [x] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added

[NickLarsenNZ]

Once ready, please add a comment with a one-liner that can be copied into the release notes (if applicable, otherwise drop the release-note label).

[siegfriedweber]

LGTM