Allow Empty Columns in CSV Header

Why it matters

This feature addresses the issue where CSV files with empty column names in their headers could cause errors or be rejected. By supporting empty column names, ClickHouse increases flexibility and compatibility with various CSV formats, making data ingestion smoother for users.

How to use it

Users can now import CSV files with headers that have empty column names without any additional configuration. Simply use the CSV format as usual when loading data, and ClickHouse will handle empty header columns gracefully.