feat: make query parameter optional in tpch benchmark

When running the tpch benchmark, the --query parameter is now optional.
If not specified, all 22 TPC-H queries will be run sequentially.

Changes:
- Make --query optional for both datafusion and ballista benchmarks
- Run all 22 queries when --query is not specified
- Only print SQL queries when --debug flag is enabled
- Write a single JSON output file for the entire benchmark run
- Fix parquet file path resolution for datafusion benchmarks
- Simplify output when iterations=1 (no iteration number, no average)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: andygrove