add kafka backend and header to json filter to http pipeline

[suchen-sci]

Json encode decode benchmark:

github.com/goccy/go-json: 12628 ns/op
std lib json: 22767 ns/op
github.com/json-iterator/go: 15210 ns/op

[samutamm]

Github analysis (revive) action identified few naming issues, please fix them.

[codecov-commenter]

Codecov Report

Merging #458 (51171b7) into main (31315af) will decrease coverage by 0.17%.
The diff coverage is 71.34%.

@@            Coverage Diff             @@
##             main     #458      +/-   ##
==========================================
- Coverage   80.07%   79.90%   -0.18%     
==========================================
  Files          76       80       +4     
  Lines        8708     8886     +178     
==========================================
+ Hits         6973     7100     +127     
- Misses       1336     1374      +38     
- Partials      399      412      +13     

Impacted Files	Coverage Δ
pkg/object/httppipeline/mock.go	0.00% <0.00%> (ø)
pkg/filter/headertojson/spec.go	68.96% <68.96%> (ø)
pkg/filter/headertojson/headertojson.go	74.62% <74.62%> (ø)
pkg/filter/kafkabackend/kafka.go	77.02% <77.02%> (ø)

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