Renaming object_name to column

[ilongin]

This PR is a follow up of #1012
Idea is to rename all public appearance of object_name to column

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.15%. Comparing base (d67d2e9) to head (5781178).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1030   +/-   ##
=======================================
  Coverage   88.15%   88.15%           
=======================================
  Files         145      145           
  Lines       12372    12372           
  Branches     1718     1718           
=======================================
  Hits        10907    10907           
  Misses       1046     1046           
  Partials      419      419           

Flag	Coverage Δ
datachain	88.08% <100.00%> (ø)

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