FIX-#5650: Restore the right dtype for applying Series.cat

[YarShev]

Signed-off-by: Igoshev, Iaroslav iaroslav.igoshev@intel.com

What do these changes do?

• first commit message and PR title follow format outlined here

  NOTE: If you edit the PR title to match this format, you need to add another commit (even if it's empty) or amend your last commit for the CI job that checks the PR title to pick up the new PR title.

• passes flake8 modin/ asv_bench/benchmarks scripts/doc_checker.py
• passes black --check modin/ asv_bench/benchmarks scripts/doc_checker.py
• signed commit with git commit -s
• Resolves BUG: AttributeError: Can only use .cat accessor with a 'category' dtype #5650
• tests added and passing
• module layout described at docs/development/architecture.rst is up-to-date

[dchigarev]

looks good as a temporary solution, left couple of comments

[dchigarev]

we've already raised a similar issue in modin, we should probably link it here as well: #2513

[YarShev]

This PR doesn't fix #2513, but only series.cat.* methods. So I think we can close #2513 when pandas has a fix on their side unless we get a P0 request to fix #2513 by that time.

[dchigarev]

Looks good for now, but we should consider closely watching for pandas-dev/pandas#51362 or, if it would get stuck, for other possible solutions in #2513, as for now categorical seems to not serve its purpose of saving memory when faced with a column-wise operation, which may result into an excessive memory consumption and out of memory issues.