feat: prototype SQL API

[westonpace]

This is a basic prototype for SQL queries. I'm a bit torn if it's useful. I think we can soon support datafusion-python. Once we can then users will have the choice of both datafusion-python and duckdb. I'm not sure if there's value in also maintaining a simple no-dependency endpoint for SQL queries.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 20.00000% with 20 lines in your changes missing coverage. Please review.

Project coverage is 77.89%. Comparing base (f257489) to head (faedd7e).
Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
rust/lance/src/datafusion/sql.rs	0.00%	20 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3132      +/-   ##
==========================================
- Coverage   77.91%   77.89%   -0.03%     
==========================================
  Files         240      241       +1     
  Lines       81564    81479      -85     
  Branches    81564    81479      -85     
==========================================
- Hits        63550    63465      -85     
- Misses      14806    14838      +32     
+ Partials     3208     3176      -32     

Flag	Coverage Δ
unittests	77.89% <20.00%> (-0.03%)	⬇️

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