Allow DataFusion type casts for Python inputs #167
Description
What
Allow DataFusion to automatically insert type casts for Python inputs.
Why
Currently we emit TypeSignature::Exact which requires users to pass exactly the types we need. That's a bit annoying for integers though, since we treat Python's int as unsigned and users would have to explicitly cast the inputs for unsigned data. We should probably emit TypeSignature::Coercible instead.
How
This is likely gonna interact with #161. Also we need to check if the variants of TypeSignatureClass are sufficient or if we need to implement a WIT bridge for LogicalType as well.