Add raw values operation

[ronensc]

No description provided.

[eranra]

Looks good to me ... no comments ... only request is to add also documentation in README so that it is well understood that choosing raw_values is different from the rest of the operations and that the values are added to the "recent raw values" field and not to the regular recent op value ... also give some explanation why this is needed.

[codecov-commenter]

Codecov Report

Merging #152 (d5cfdbf) into main (6668d30) will increase coverage by 0.26%.
The diff coverage is 63.26%.

@@            Coverage Diff             @@
##             main     #152      +/-   ##
==========================================
+ Coverage   58.46%   58.72%   +0.26%     
==========================================
  Files          51       54       +3     
  Lines        2949     3084     +135     
==========================================
+ Hits         1724     1811      +87     
- Misses       1113     1152      +39     
- Partials      112      121       +9     

Flag	Coverage Δ
unittests	58.72% <63.26%> (+0.26%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pkg/pipeline/utils/convert.go	18.18% <18.18%> (ø)
pkg/pipeline/encode/encode_prom.go	81.85% <59.09%> (+0.77%)	⬆️
pkg/pipeline/extract/aggregate/aggregate.go	95.08% <100.00%> (+0.21%)	⬆️
pkg/test/utils.go	82.22% <100.00%> (-0.20%)	⬇️
pkg/config/config.go	50.00% <0.00%> (ø)
pkg/pipeline/write/write_stdout.go	100.00% <0.00%> (ø)
pkg/pipeline/ingest/ingest_kafka.go	85.85% <0.00%> (ø)
pkg/pipeline/decode/decode_protobuf.go	74.54% <0.00%> (ø)
pkg/pipeline/ingest/ingest_grpc.go	61.53% <0.00%> (ø)
... and 3 more

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[ronensc]

@KalmanMeth @eranra Please pay attention to the added documentation. Is it clear enough?

[eranra]

Minor updates to doc .... looks good to me. LGTM