ZOOKEEPER-4955: [ADDENDUM] Refactor Ca, Cert and etc. so to be reusable

[kezhuw]

This is a fixup commit to #2292. It contains only test code changes to make SSL related classes, e.g. Ca, Cert and etcd., to be reusable.

[kezhuw]

@anmolnar Would you like to take a look at this ? It is a fixup commit to #2292(ZOOKEEPER-4955) and touchs only test codes.

[anmolnar]

Yeah, it makes perfect sense to make this framework reusable. Have you generated it with some AI?

[kezhuw]

Have you generated it with some AI?

No. But I do use IntelliJ IDEA in this refactoring, not sure whether the code completions/suggestions(line by line, it will recommend you public CertSigner withExpiration(Duration expiration) {} or this.expiration = expiration;) are backed by AI.

[anmolnar]

Have you generated it with some AI?

No. But I do use IntelliJ IDEA in this refactoring, not sure whether the code completions/suggestions(line by line, it will recommend you public CertSigner withExpiration(Duration expiration) {} or this.expiration = expiration;) are backed by AI.

I dunno, but it's pretty impressive how quickly you were able to create the framework. Borrowed from other project or wrote from scratch?

[kezhuw]

Borrowed from other project or wrote from scratch?

From scratch. But I do write tls related tests code in rust, they probably have something in common despite the language.

https://github.com/kezhuw/zookeeper-client-rust/blob/4ae35472bf8545ee3462aaf287e9359ae8953644/src/tls/client.rs#L211