Let secret op create pkcs12 stores

[maltesander]

Description

• removed copying of keystores, now accessed directly vom secret-op moints (nothing is added)
• do not import system trust store anymore
• removed prepare container

fixes #618

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
- [x] Changes are OpenShift compatible
- [x] CRD changes approved
- [x] Helm chart can be installed and deployed operator works
- [ ] Integration tests passed (for non trivial changes)
- [x] Changes need to be "offline" compatible

# Reviewer
- [ ] Code contains useful comments
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated
- [ ] Changelog updated
- [ ] 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

[sbernauer]

I would have excepted much more simplification similar to stackabletech/zookeeper-operator#695,
as in the case of Kafka I think we don't need to add additional certs to trust and keystore, so we should be able to straight up mount and use trust and keystores.

[maltesander]

test: https://ci.stackable.tech/view/02%20Operator%20Tests%20(custom)/job/kafka-operator-it-custom/48/

[sbernauer]

Awesome, really like this!

[sbernauer]

Thanks!