gh-143658: importlib.metadata: Use `str.translate` to improve performance of `importlib.metadata.Prepared.normalized` (#143660)

Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Bartosz Sławecki <bartosz@ilikepython.com>