test: Set -logthreadnames in unit tests #19028

Generally the unit tests are single threaded, with the exception of the script check threads, the schedule, and optionally indexer threads.

Like the functional tests, the thread name can serve additional debug information, so set -logthreadnames in unit tests.

Can be tested with

./src/test/test_bitcoin -l test_suite -t validation_tests/test_combiner_all -- DEBUG_LOG_OUT

Concept ACK

At some point we may just consider enabling threadnames by default; I don't think there's any noticeable performance penalty, but I can bench to verify.

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Conflicts

Reviewers, this pull request conflicts with the following ones:

• #19064 (refactor: Cleanup thread ctor calls by hebasto)
• #18925 (Add extra thread for scheduler, move TorControl and OpenAddedConnections to scheduler by naumenkogs)

If you consider this pull request important, please also help to review the conflicting pull requests. Ideally, start with the one that should be merged first.

I'm not convinced on enabling logging of thread names by default, though more convenient during development, I think it increases the size of the log entries and files for something not useful for most users. But for the tests it makes a lot of sense. Also the unifying of how to create the scheduler thread makes sense. Though we need to move away from the boost thread group at some point. ACK 99993489da9bc003b823bcab10e5f5297b369431