fix: map HTTP response status code to equivalent GRPC Status code

[tim-mwangi]

Description

Need to map the HTTP status code returned by the filter logic to GRPC status code for GRPC instrumentation.

Testing

Unit tests.

Checklist:

• [ ✅ ] My changes generate no new warnings
• [ ✅ ] I have added tests that prove my fix is effective or that my feature works
• [✅ ] Any dependent changes have been merged and published in downstream modules

[codecov]

Codecov Report

Merging #207 (2404d24) into main (b433f7a) will increase coverage by 0.47%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #207      +/-   ##
==========================================
+ Coverage   58.91%   59.38%   +0.47%     
==========================================
  Files          55       55              
  Lines        2222     2243      +21     
==========================================
+ Hits         1309     1332      +23     
+ Misses        855      853       -2     
  Partials       58       58              

Impacted Files	Coverage Δ
...k/instrumentation/google.golang.org/grpc/server.go	75.40% <100.00%> (ø)
...k/instrumentation/google.golang.org/grpc/status.go	32.53% <100.00%> (ø)

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