Add a Binary format to store test aggregates

[Swatinem]

This defines a binary file format similar to the various cache formats we use in Symbolicator.

The format contains various aggregations for a configurable number of days.

[codecov]

Codecov Report

Attention: Patch coverage is 97.65494% with 28 lines in your changes missing coverage. Please review.

Project coverage is 93.59%. Comparing base (c840502) to head (411e84a).
Report is 2 commits behind head on main.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/binary/bindings.rs	90.65%	10 Missing ⚠️
src/binary/format.rs	94.01%	10 Missing ⚠️
src/binary/error.rs	0.00%	6 Missing ⚠️
src/binary/writer.rs	99.43%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #51      +/-   ##
==========================================
+ Coverage   85.34%   93.59%   +8.24%     
==========================================
  Files           5       14       +9     
  Lines         587     1780    +1193     
==========================================
+ Hits          501     1666    +1165     
- Misses         86      114      +28     

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[codecov-notifications]

Codecov Report

Attention: Patch coverage is 97.65494% with 28 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/binary/bindings.rs	90.65%	10 Missing ⚠️
src/binary/format.rs	94.01%	10 Missing ⚠️
src/binary/error.rs	0.00%	6 Missing ⚠️
src/binary/writer.rs	99.43%	2 Missing ⚠️

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[Swatinem]

I believe this should be feature complete now.
I would appreciate a review, and would be happy to schedule another meeting to walk through the code or through the feedback / questions.