HfArgumentParser: allow for hyhenated field names in long-options (#33990)
Allow for hyphenated field names in long-options
argparse converts hyphens into underscores before assignment (e.g., an
option passed as `--long-option` will be stored under `long_option`), So
there is no need to pass options as literal attributes, as in
`--long_option` (with an underscore instead of a hyphen). This commit
ensures that this behavior is respected by `parse_args_into_dataclasses`
as well.
Issue: #33933
Co-authored-by: Daniel Marti <mrtidm@amazon.com>