This pull request is mainly for adding experimental new Java client as well as gRPC support. Please be aware that APIs are subject to change without any notice, until 0.4.0.

Key Changes

• adaptive integration test and categorized test cases(under unit or integration group)
• JPMS support(incomplete) along with multi-release jar file and JDK 17 support
• use com.clickhouse as package name and maven group id
  Note: clickhouse-jdbc still uses ru.yandex as before, but it will be changed starting from 0.4.0.
• more features being added into clickhouse-client module:
  • async execution(by default)
  • better support of RowBinary format, and more data types like Date32, Geo types, and nested data types etc.
  • fluent API with builder classes
  • named parameter support
  • stream API via ClickHouseResponse.recordStream()
• experimental gRPC support in clickhouse-grpc-client
• renamed clickhouse-native-client to clickhouse-tcp-client (still empty there :p)

Known Issues about the gRPC client

• query may hang if you're using an old version of ClickHouse - see grpc query hangs in ClickHouse 21.3 and 21.6 ClickHouse#27024
• compression is not supported well - see Improve gRPC compression support ClickHouse#28671
  Note: you may want to disable compression for better performance.
• server reports "session is locked" when executing multiple queries in one go - might be a bug at client side

TODOs - will address in separate PRs

• clickhouse-client
  • re-write ClickHouseCluster
  • sort out exceptions for better error handling
  • primitive array support
• clickhouse-grpc-client
  • custom registry for compression/decompression
  • ssl/tls support
  • support extremes
  • shaded jar with only netty(for building native image later)
• clickhouse-jdbc
  • change driver to com.clickhouse.jdbc.ClickHouseDriver but keep the old one as sub-class
  • refactor to build on top of clickhouse-client
  • switch to RowBinary format