[DOP-19784] - add search_vector to Transfer model

[maxim-lixakov]

Change Summary

• add search_vector with GIN indexed to Transfer table
• add following tests

Related issue number

Checklist

• Commit message and PR title is comprehensive
• Keep the change as small as possible
• Unit and integration tests for the changes exist
• Tests pass on CI and coverage does not decrease
• Documentation reflects the changes where applicable
• docs/changelog/next_release/<pull request or issue id>.<change type>.rst file added describing change
  (see CONTRIBUTING.rst for details.)
• My PR is ready to review.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.83%. Comparing base (2967c7f) to head (be27a5c).
Report is 89 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop      #92      +/-   ##
===========================================
+ Coverage    92.77%   92.83%   +0.06%     
===========================================
  Files           84       85       +1     
  Lines         2435     2456      +21     
  Branches       301      302       +1     
===========================================
+ Hits          2259     2280      +21     
  Misses         125      125              
  Partials        51       51              

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