Add exception handling mode

[ashulenko]

Working on not Apache Flink-related project we were in need to put data to ClickHouse and we expanded current sink. Here is the list is the most important improvements and changes:

• Changing naming of ClickHouse (converting letter "h" to uppercase);
• Add exception handling with CompletableFuture;
• ClickHouse sending exception handling config was added:

1. if ignoring-clickhouse-sending-exception-enabled is true, exception while clickhouse sending is ignored and failed data automatically goes to the disk.
2. if ignoring-clickhouse-sending-exception-enabled is false, clickhouse sending exception thrown in "main" thread (thread which called ClickhHouseSink::invoke) and data also goes to the disk.

[ashulenko]

Merged into master #12