test: prepare junit file attribute normalization

Add file attribute normalization in JUnit test output transform to
support upcoming file attribute feature in JUnit XML reporter.

PR-URL: nodejs#59432
Fixes: nodejs#59422
Reviewed-By: Moshe Atlow <[email protected]>
Reviewed-By: Chemi Atlow <[email protected]>
Reviewed-By: Pietro Marchini <[email protected]>

Author: Han5991