refactor(query engine): introduce Column type

[forshev]

Description

Add Column abstraction that supports getting value of Records's column at Column.idx index

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 91.66667% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.02%. Comparing base (5a04fb0) to head (e02c3a5).

Files with missing lines	Patch %	Lines
query/column.go	89.58%	5 Missing ⚠️
storeapi/grpc_stream_search.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@                    Coverage Diff                    @@
##           0-record-dont-use-any     #548      +/-   ##
=========================================================
+ Coverage                  76.86%   77.02%   +0.16%     
=========================================================
  Files                        248      249       +1     
  Lines                      18890    18910      +20     
=========================================================
+ Hits                       14519    14566      +47     
+ Misses                      4371     4344      -27     

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