Dbt-clickhouse

Improvement
- Lots of work on Distributed table materializations. Big thanks to [gfunc](https://github.com/gfunc) for the additional PR
and [Zhenbang](https://github.com/zli06160) for code review and suggestions. See the README for details on how to
use the new functionality.
Bug Fix
- dbt would fail if a cluster name contained a dash. This has been fixed. Thanks to [Andy](https://github.com/the4thamigo-uk
for the PR

Bug Fix
- Fixed issues with experimental Distributed table materializations. Closes https://github.com/ClickHouse/dbt-clickhouse/issues/179.
Thanks to [Zhebnang](https://github.com/zli06160) for the report and for contributing to the fix with [gfunc](https://github.com/gfunc).

Bug Fix
- Fixed an exception in "legacy" incremental materializations that are not distributed

Bug fix
- Lightweight deletes could fail in environments where the HTTP session was not preserved (such as clusters behind a non-sticky
load balancer). This has been fixed by sending the required settings with every request instead of relying on a SET statement.
A similar approach has been used to persist the 'insert_distributed_sync' setting for Distributed table materializations.

Improvement
- Adds additional experimental support for Distributed table engine models and incremental materialization. See the README for
details. Thanks to [gladkikhtutu](https://github.com/gladkikhtutu) for the contribution!

Bug Fixes
- Fixed two logging/exception handling issues that would cause exception on startup or when handling some exceptions
from the ClickHouse server. Partially addresses https://github.com/ClickHouse/dbt-clickhouse/issues/169.
- Fixed issue with the `on_cluster` macro that would break the exchange tables step of incremental materializations
with an active cluster. Thanks to [Andrew Davis](https://github.com/Savid) for the PR. Closes
https://github.com/ClickHouse/dbt-clickhouse/issues/167