Backporting the Python 3 implementation of setStream
to ClosingFileHandler as a fallback within Python 2.
Reported-by: Jay Satiro
Fixes#6259Closes#6270
Make sure the log file is not locked once a test has
finished and align with the behavior of our logmsg.
Rename curl_test_data.py to be a general util.py.
Format and sort Python imports with isort/VSCode.
Bug: #6058Closes#6206