Improve compute function FFI

[paleolimbot]

This should be able to export:

• DataFusion scalar function
• DataFusion table function
• Arrow C++ Scalar function
• Arrow C++ Aggregate function
• Any file reader that can export an ArrowArray
• A data source based on a SQL query + parameters from an AdbcConnection (with a lot of mutexes)

This should be able to be imported and used as a:

• DataFusion scalar function
• DataFusion table function
• Arrow C++ Scalar function
• DuckDB scalar function
• DuckDB table function

...obviously that needs some testing, but the concepts are intended to line up:

• "bind" / "return_type" / "KernelState::Resolver" == bind (computes output type from input type)
• Various combinations of clone/push/pull can accomodate per-batch computation (i.e., DataFusion's invoke_batch, DuckDB's "function") and aggregation of multiple batches into a single value (Arrow's ScalarAggregate function, DataFusion's accumulator, one stage of DuckDB's aggregator)
• Arrow C++-based and nanoarrow-based implementations should be able to respect the custom allocator; DuckDB and Arrow C++ should be able to provide the custom allocator (DataFusion doesn't have a non-default allocator that I could find documentation on)

This doesn't handle pre-allocated output (maybe DuckDB, Arrow C++). Most geo functions don't benefit from this anyway (very few fixed-width -> fixed width transformations that are cheap enough that they could reuse the input allocation).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.00%. Comparing base (db02936) to head (e8113af).
⚠️ Report is 42 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #113      +/-   ##
==========================================
- Coverage   94.53%   93.00%   -1.53%     
==========================================
  Files          25       29       +4     
  Lines        4132     4418     +286     
==========================================
+ Hits         3906     4109     +203     
- Misses        226      309      +83     

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