Fix: Resolve Sequence type hints and add from_jsonl alias (#5354)

[2k33cse992574]

Fixes #5354

Proposed Changes

• Updates features typing to use Sequence instead of List/Tuple in from_json and from_parquet parsing functions.
• Adds from_jsonl as an explicit wrapper to from_json for dataset creation, providing API symmetry with to_jsonl.
• Includes dedicated tests for the new from_jsonl alias in all standard loaders.