Clickhouse-connect

Improvement
- Added Python 3.12 wheels and CI tests. Note that PyArrow is not yet available for 3.12, but should be soon. See https://github.com/apache/arrow/issues/37880
- The main `clickhouse-connect.get_client` method now displays type hints and ignores non-keyword arguments. Thanks to
[Avery Fischer](https://github.com/biggerfisch) for the usability improvement!
- Log messages regarding C optimization availability and JSON library selection have been change from INFO to DEBUG. Closes
https://github.com/ClickHouse/clickhouse-connect/issues/249

Bug Fixes
- Fixed insert error when inserting a zero length string into a FixedString column. Closes https://github.com/ClickHouse/clickhouse-connect/issues/244
- Removed unnecessary validate_entrypoints import from top level package __init__ that was breaking Python 3.7. Note that Python 3.7 is EOL
and will no longer be supported as of January 1, 2024.

Bug Fix
- Fixed an issue with the automatic retry of "connection reset errors". This should prevent exceptions when the
ClickHouse server closes a Keep Alive connection while a new request is in flight.

Improvement
- Improved support for typing tools by adding a `py.typed` file. Thanks to [Avery Fischer](https://github.com/biggerfisch)
for the contribution.

Bug Fix
- Nested empty Maps would return an IndexError when queried. https://github.com/ClickHouse/clickhouse-connect/issues/239. Thanks
to [Ashton Hudson](https://github.com/CaptainCuddleCube) for the report and the fix

Bug fixes
- Inserts using Pandas 2.1 would fail due to a removed method in the Pandas library. There is now a workaround/fix for
this. Closes https://github.com/ClickHouse/clickhouse-connect/issues/234
- Inserts into a FixedString column that were not the expected size could cause corrupt insert blocks and mysterious errors
from the ClickHouse server. Validation has been added so that more meaningful error messages are generated if a fixed string
value is an invalid size. A reminder that strings which are "too short" for a FixedString column will be padded with 0 bytes, while
strings that are "too long" will generate an exception during the insert.

Improvement
- Add support and tests for the `Object(Nullable('json'))` type, which is sometimes detected by schema inference.