KAFKA-10000: Add new preflight connector config validation logic (KIP-618)

[C0urante]

Implements the preflight validation logic described in KIP-618.

Relies on changes from:

• KAFKA-10000: Widely-used utility methods (KIP-618) #11774
• KAFKA-10000: Add all public-facing config properties related to exactly-once source support (KIP-618) #11775

[C0urante]

Converting to draft until upstream PRs are reviewed.

[C0urante]

Given that all merge conflicts have been resolved and #11775 has already been approved, marking this as ready for review.

[C0urante]

@showuon the 3.3.0 feature freeze is a little over a month away and there are still seven open pull requests for this feature. Do you have time to take a look?

[C0urante]

@showuon If you do not have time to take a look, is there anyone you can recommend in your place?

[C0urante]

@showuon hello? Is anyone actually maintaining Kafka Connect anymore or should we all just stop contributing to it?

[tombentley]

A few nits, but LGTM

[tombentley]

Is it safe to assume validatedName != null at this point?

[C0urante]

Yes; every framework-level connector property should have a ConfigValue entry in the map here.

[tombentley]

Factor out this else if/else logic into a method, since it's the same between the connectorUsesConsumer and connectorUsesAdmin methods?

[C0urante]

👍 done.

[tombentley]

Could we assert on error message equality (or contains if there can be more than one)? As well was making the tests clearer it would make it clearer that we're actually hitting the expected validation condition.

[C0urante]

Ack, done.

[C0urante]

Thanks Tom, addressed the nits.

[mimaison]

Thanks @C0urante !