Reduce default log verbosity for itests

[masih]

The log output for itests is so verbose that in cases GitHub Actions UI recommends downloading the log to look at it as it refuses to render it all on the page. They make seeing the cause of failures cumbersome.

• Change the default log levels for itests to print nothing.
• Add utilities to easily enable verbose logging manually for failing tests.

[rjan90]

2024-10-08:
From triage meeting:

• Ideally on failure get debug logs, else print nothing
• Dump all logs to a file as a test artifact that way if there is a failure it can still be seen but it doesn't clutter standard output in GitHub UI. (This was the recommended approach in the UI.)