feat(transport): add JSON codec for gRPC

[tonybase]

No description provided.

[codecov-commenter]

Codecov Report

Merging #1908 (a59a7b3) into main (558ef4e) will decrease coverage by 0.25%.
The diff coverage is 28.57%.

@@            Coverage Diff             @@
##             main    #1908      +/-   ##
==========================================
- Coverage   80.85%   80.59%   -0.26%     
==========================================
  Files          80       81       +1     
  Lines        3573     3587      +14     
==========================================
+ Hits         2889     2891       +2     
- Misses        477      489      +12     
  Partials      207      207              

Impacted Files	Coverage Δ
transport/grpc/codec.go	28.57% <28.57%> (ø)
internal/context/context.go	97.01% <0.00%> (-2.99%)	⬇️

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