Allow BOM parsing in TSV when first column cannot contain BOM values

Why it matters

This feature addresses the issue where TSV files with a BOM in the first column would fail to parse correctly. By allowing BOM parsing when the first column cannot contain BOM characters, it improves compatibility and robustness when importing TSV data.

How to use it

Users can import TSV files containing a BOM without additional configuration. The parser automatically detects and handles the BOM if the first column's data cannot contain BOM characters.