[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 (0149883) with main (d243cee)}

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 78.32%. Comparing base (d243cee) to head (0149883).
Report is 1 commits behind head on main.

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   78.32%   78.32%           
=======================================
  Files         611      611           
  Lines       72421    72427    +6     
=======================================
+ Hits        56725    56730    +5     
- Misses      15696    15697    +1     

Files with missing lines	Coverage Δ
src/daft-local-execution/src/sources/scan_task.rs	73.02% <100.00%> (+1.07%)	⬆️
src/daft-micropartition/src/micropartition.rs	90.50% <100.00%> (-0.33%)	⬇️
src/daft-micropartition/src/python.rs	78.23% <94.73%> (+1.55%)	⬆️

... and 3 files with indirect coverage changes