feat: cache miniblock metadata

[westonpace]

The miniblock chunk data was always intended to be cached. This is essential for good random access performance. This PR adds that caching.

[westonpace]

Leaving in draft until #3321 is merged

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 73.98374% with 32 lines in your changes missing coverage. Please review.

Project coverage is 78.90%. Comparing base (c0c1b53) to head (02b6f82).

Files with missing lines	Patch %	Lines
rust/lance-datagen/src/generator.rs	0.00%	22 Missing ⚠️
.../lance-encoding/src/encodings/logical/primitive.rs	89.88%	5 Missing and 4 partials ⚠️
rust/lance-core/src/utils/path.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3323      +/-   ##
==========================================
- Coverage   78.92%   78.90%   -0.02%     
==========================================
  Files         246      246              
  Lines       87805    87903      +98     
  Branches    87805    87903      +98     
==========================================
+ Hits        69298    69363      +65     
- Misses      15629    15660      +31     
- Partials     2878     2880       +2     

Flag	Coverage Δ
unittests	78.90% <73.98%> (-0.02%)	⬇️

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