create source jar and update examples

[zhicwu]

Summary

Create source jars and update examples

Checklist

Delete items not relevant to your PR:

• Unit and integration tests covering the common scenarios were added
• A human-readable description of the changes was provided to include in CHANGELOG
• For significant changes, documentation in https://github.com/ClickHouse/clickhouse-docs was updated with further explanations or tutorials

[zhicwu]

Build failures are unrelated.