KafkaSinkCluster scram_over_mtls - full integration tests

[rukai]

This PR extends the test cases added in #1652
It introduces a very similar case, run on a fresh shotover instance but running the stages of the test in a different order, in an effort to find possible token usage edge cases.

In doing so it uncovered a race condition in shotover.
When parsing metadata responses, we were previously updating the local nodes list only when the node was new globally.
However this is incorrect, we may still need to update the local nodes list even if the node is not new globally.
So this PR fixes this issue by pulling self.update_local_nodes() out of the if new { statement.

I've also left in a debug implementation for KafkaNode since I've found that we often want to be able to include it in temporary debug logs when investigating kafka bugs.

[codspeed-hq]

CodSpeed Performance Report

Merging #1651 will not alter performance

_{Comparing rukai:scram_over_mtls_tests (0f3d3a2) with main (796e346)}

Summary

✅ 37 untouched benchmarks