feat: standalone vector transform stage

[westonpace]

This makes the vector transform stage a standalone operation.

[westonpace]

Leaving in draft as this is dependent on #2556 and #2562 which are still awaiting review

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 5.40541% with 35 lines in your changes missing coverage. Please review.

Project coverage is 79.94%. Comparing base (b3ad008) to head (0939ebf).
Report is 7 commits behind head on main.

Files	Patch %	Lines
rust/lance/src/index/vector/ivf/builder.rs	0.00%	35 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2566      +/-   ##
==========================================
- Coverage   80.00%   79.94%   -0.06%     
==========================================
  Files         209      209              
  Lines       59847    59949     +102     
  Branches    59847    59949     +102     
==========================================
+ Hits        47880    47928      +48     
- Misses       9143     9186      +43     
- Partials     2824     2835      +11     

Flag	Coverage Δ
unittests	79.94% <5.40%> (-0.06%)	⬇️

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[eddyxu]

Pending CI