[SPARK-52627] Improve SQLTests to handle userName

[dongjoon-hyun]

What changes were proposed in this pull request?

This PR aims to improve SQLTests to handle userName additionally.

Why are the changes needed?

This is helpful in case of running Spark Connect Server without docker images. For example, when building and running from the source instead of Docker image.

Does this PR introduce any user-facing change?

No behavior change.

How was this patch tested?

Pass the CIs.

Build and run from the source

$ build/sbt package
$ cd sbin/
$ SPARK_NO_DAEMONIZE=1 ./start-connect-server.sh

Test

$ swift test --filter SQLTests
...
✔ Test runAll() passed after 2.719 seconds.
✔ Suite SQLTests passed after 2.723 seconds.
✔ Test run with 5 tests passed after 2.723 seconds.

Was this patch authored or co-authored using generative AI tooling?

No.

[dongjoon-hyun]

Thank you! Merged to main.