feat: Parse gzip header

[effigies]

Builds on #2090.

[codecov]

Codecov Report

Attention: Patch coverage is 84.09091% with 7 lines in your changes missing coverage. Please review.

Project coverage is 87.66%. Comparing base (b9f975c) to head (2faf391).
Report is 4 commits behind head on master.

Files	Patch %	Lines
bids-validator/src/schema/context.ts	63.63%	4 Missing ⚠️
bids-validator/src/files/gzip.ts	90.90%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2092      +/-   ##
==========================================
+ Coverage   85.69%   87.66%   +1.96%     
==========================================
  Files          91      132      +41     
  Lines        3782     6834    +3052     
  Branches     1220     1633     +413     
==========================================
+ Hits         3241     5991    +2750     
- Misses        455      751     +296     
- Partials       86       92       +6     

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