Clickhouse-connect

Bug Fix
- Inserts into decimal columns first convert the source value to a Python Decimal to work around floating point
rounding issues. Fixes https://github.com/ClickHouse/clickhouse-connect/issues/203
- DateTime64 values were broken for dates before 01-01-1970. This is fixed. https://github.com/ClickHouse/clickhouse-connect/issues/204

Improvements
- Cython version upgraded to 3.0.0b3
- Inserts for string columns are now C optimized (approximately 2x faster)

Bug Fix
- Very long running queries could break because ClickHouse returned too many progress headers. Thanks to
[Ivan](https://github.com/istrebitel-1) for the fix

Improvements
Minor documentation clean up regarding Superset compatibility

Bug Fixes
- Use uuid4 instead of uuid1 for generating client level session_ids, as well as use a new urllib3 PoolManager
when multiprocessing mode is detected. This should fix https://github.com/ClickHouse/clickhouse-connect/issues/194.
Thanks to [Guillaume Matheron](https://github.com/guillaumematheron) for filing the issue and digging into details.
The underlying problem is that the Python uuid1() is not guaranteed to be unique in a `forked` multiprocessing environment.
- Change log warning to debug message if numpy is not available for C bindings. This check is harmless if numpy
is not installed and should not have produced a warning. Fixes https://github.com/ClickHouse/clickhouse-connect/issues/195

Improvements
- Cython version upgraded to 3.0.0b2
- The block size (number of rows) for chunked/streaming inserts is now dynamically determined based on sample of
the insert data. This allows more efficient streaming of large inserts and significantly improves insert performance
in some circumstances.
- Pivoting row based data to native columns for inserts has been optimized in C. This improves insert performance
for large inserts of row oriented data.

Bug Fix
- The client will now validate that the `client_protocol_version` query parameter is actually received and used by the ClickHouse
server before assuming that data returned confirms to the expected protocol version. This fixes an incompatibility with the
current versions of CHProxy (and possibly other proxies that restrict the query parameters passed to the ClickHouse Server).
Note that other features that require the use of query parameters (such as server side bound query parameters) may also fail
because of this behavior in CHProxy. Fixes https://github.com/ClickHouse/clickhouse-connect/issues/191

Bug Fixes
- The client `command` method now accepts ClickHouse "external data." Closes https://github.com/ClickHouse/clickhouse-connect/issues/186
- Arrays of Python date and datetime objects are now correctly formatted when use as server side parameters. Fixes https://github.com/ClickHouse/clickhouse-connect/issues/188
- Fixed inserts of SimpleAggregateFunction columns with a LowCardinality type parameter. https://github.com/ClickHouse/clickhouse-connect/issues/187