[SPARK-58573][INFRA][BUILD] Replace defunct Jenkins test grouping with modern GitHub Actions grouping

[nchammas]

What changes were proposed in this pull request?

Remove the old CURRENT_BLOCK and ERROR_CODES testing infrastructure and replace it with an updated titled_block context manager that also groups log output on GitHub Actions.

Make sure that title blocks cannot be nested, and that all large blocks of output have a suitable title block at the top level main() function.

Fold group_in_github_actions into the new titled_block.

Remove build_spark_documentation, which is not used by anything.

Why are the changes needed?

Amusingly, I added the old testing infrastructure 12 years ago in #2606. It was built for Jenkins, which we do not use anymore. The block and error codes are not used by any part of our current test infrastructure on GitHub Actions.

The new titled_block context manager takes care of printing block titles as before, and also subsumes the log grouping behavior from group_in_github_actions (introduced in #54524) since it is useful for more than just sbt.

We have a separate job for building the docs, so I assume we don't want to revive the currently-dead build_spark_documentation.

Does this PR introduce any user-facing change?

No.

How was this patch tested?

CI for this PR. Some illustrative screenshots of the new log groups:

The purple debug lines are from my fork and are not related to this PR.

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

I wrote this with assistance from GitHub Copilot.

[nchammas]

cc @gaogaotiantian since you authored #54524.