Inconsistent behavior on insert with_column_types

[ergoithz]

Passing both params and with_column_types to Client.execute('INSERT INTO ...', params=[...], with_column_types=True) will violate the interface by neither returning a tuple nor raising an exception about with_column_types not being compatible.

This behavior is documented in the result section of Client.execute API documentation, could be maybe improved to avoid confusion.

One would expect one of these outcomes:

• A tuple with (result, None) (None meaning no column definitions).
• An exception stating with_column_types cannot be True.

This behavior should also be reflected in the documentation.

Versions up to 0.2.6

The issue is about client code interfaces, both python and clickhouse versions are irrelevant.