Part 4: read_table.c uses transform in ffi

[nicklan]

Stacked PR. Only review these commits

What changes are proposed in this pull request?

Use new transform functionality to transform data over FFI.

This lets us get rid of all the gross partition adding code in c :)

Still some things to work out here wrt. ffi types, so this is very much a draft.

But it works.

How was this change tested?

[codecov]

Codecov Report

Attention: Patch coverage is 70.80537% with 87 lines in your changes missing coverage. Please review.

Project coverage is 83.24%. Comparing base (c3a868f) to head (b961220).

Files with missing lines	Patch %	Lines
ffi/src/scan.rs	0.00%	33 Missing ⚠️
ffi/src/engine_funcs.rs	66.17%	23 Missing ⚠️
kernel/src/scan/log_replay.rs	86.53%	7 Missing and 7 partials ⚠️
ffi/src/expressions/kernel.rs	0.00%	13 Missing ⚠️
kernel/src/scan/mod.rs	95.58%	0 Missing and 3 partials ⚠️
kernel/src/engine/arrow_expression.rs	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #614      +/-   ##
==========================================
- Coverage   83.45%   83.24%   -0.21%     
==========================================
  Files          74       74              
  Lines       16877    17080     +203     
  Branches    16877    17080     +203     
==========================================
+ Hits        14084    14218     +134     
- Misses       2135     2201      +66     
- Partials      658      661       +3     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[scovich]

What is the duckdb story with this new approach/PR? Have we explored that yet?

Asking because IIRC they push partition values down into their parquet reader, so they'll need to introspect the transforms and handle them differently than any kernel code we've written.

[scovich]

Don't we need to free data and evaluator regardless of whether this transform succeeded?