feat: add parse_raw_upload

[joseph-sentry]

we want to support parsing raw upload files instead of individual JUnit
XML files

the input of this new function is the raw upload in byte form

the output is a messagepacked binary payload containing the results of
the parsing and the raw upload in readable format in byte form

Depends on: #62

[codecov-notifications]

Codecov Report

Attention: Patch coverage is 88.05970% with 8 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/raw_upload.rs	89.28%	6 Missing ⚠️
src/testrun.rs	80.00%	2 Missing ⚠️

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[codecov]

Codecov Report

Attention: Patch coverage is 88.05970% with 8 lines in your changes missing coverage. Please review.

Project coverage is 89.48%. Comparing base (996ecb2) to head (e69c111).

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/raw_upload.rs	89.28%	6 Missing ⚠️
src/testrun.rs	80.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #63      +/-   ##
==========================================
+ Coverage   88.68%   89.48%   +0.79%     
==========================================
  Files           5        6       +1     
  Lines         707      770      +63     
==========================================
+ Hits          627      689      +62     
- Misses         80       81       +1     

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