FIX-#7383: Avoid broadcast issue in partition manager with custom NPartitions

[anmyachev]

What do these changes do?

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• 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: operations with NPartitions not a power of 2 fails in some cases. BUG IN PARTITON_MANAGER?. possible solution in here! #7383
• tests added and passing
• module layout described at docs/development/architecture.rst is up-to-date