imports: deprecate from pkg root [4/n] Retrieval

[Borda]

What does this PR do?

Part of #1681 (comment)

• class version
• functional
• tests

Before submitting

• Was this discussed/agreed via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure to update the docs?
• Did you write any new necessary tests?

PR review

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

Did you have fun?

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[codecov]

Codecov Report

Merging #1699 (1edbe5c) into master (1056c26) will decrease coverage by 50%.
The diff coverage is 71%.

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #1699     +/-   ##
========================================
- Coverage      89%     38%    -50%     
========================================
  Files         232     234      +2     
  Lines       12983   13084    +101     
========================================
- Hits        11494    4985   -6509     
- Misses       1489    8099   +6610