[CHORE] Enable lancedb reads for native executor

[colin-ho]

Enables Lance reads for swordfish.

The existing lance read mechanism reads from python iterators. This PR abstracts out that logic to a separate function.

Both the python and streaming executors will call this function, the python executor will do a .collect on the iterator, while the native runner will wrap the iterator in a stream.

[codspeed-hq]

CodSpeed Performance Report

Merging #2925 will not alter performance

_{Comparing colin/swordfish-lance-reads (2e23e47) with main (73ff3f3)}

Summary

✅ 17 untouched benchmarks

[codecov]

Codecov Report

Attention: Patch coverage is 95.06173% with 4 lines in your changes missing coverage. Please review.

Project coverage is 78.48%. Comparing base (73ff3f3) to head (2e23e47).

Files with missing lines	Patch %	Lines
src/daft-micropartition/src/python.rs	94.73%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2925      +/-   ##
==========================================
+ Coverage   78.14%   78.48%   +0.33%     
==========================================
  Files         610      610              
  Lines       72146    71752     -394     
==========================================
- Hits        56381    56315      -66     
+ Misses      15765    15437     -328     

Files with missing lines	Coverage Δ
src/daft-local-execution/src/sources/scan_task.rs	83.41% <100.00%> (+1.46%)	⬆️
src/daft-micropartition/src/micropartition.rs	90.47% <100.00%> (-0.33%)	⬇️
src/daft-micropartition/src/python.rs	78.29% <94.73%> (+1.55%)	⬆️

... and 15 files with indirect coverage changes