Fix output path argument bug in `build_sequences_per_dataset` script

[DhineshPonnarasan]

Summary

The script build_sequences_per_dataset.py defines the CLI argument --per-dataset-sequences-path, but later writes to a different non-existent argument name. This causes a runtime failure when saving output.

Problem

In build_sequences_per_dataset.py, the script uses args.path_to_sequences_per_dataset_json, but that field is never defined by argparse.

The defined argument is:

--per-dataset-sequences-path

Steps to Reproduce

1. Run the script with valid data arguments and:

   --per-dataset-sequences-path out.json

2. Let the script reach the output-writing section.
3. Observe an AttributeError for missing path_to_sequences_per_dataset_json.

Expected Behavior

The script should write JSON output to the path provided by --per-dataset-sequences-path and finish successfully.

Proposed Fix

1. Replace:

   args.path_to_sequences_per_dataset_json

   with:

   args.per_dataset_sequences_path

   in:

   • build_sequences_per_dataset.py

2. Optional cleanup:

   • Fix malformed help text so train, valid, test key names are formatted correctly.

Acceptance Criteria

• Script runs without AttributeError.
• Output JSON file is created at the path passed to --per-dataset-sequences-path.
• Console success message prints the correct output path.

[Phlip79]

Thank you, I have suggested changes in the PR.