fix: add proper checks for Hierarchical PartionKeys

PR Checklist

Please check if your PR fulfills the following requirements:

• [ ] The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• [ ] Bugfix
• [ ] Feature
• [ ] Code style update (formatting, local variables)
• [ ] Refactoring (no functional changes, no api changes)
• [ ] Build related changes
• [ ] CI related changes
• [ ] Other... Please describe:

What is the current behavior?

Issue Number: #1165

What is the new behavior?

Does this PR introduce a breaking change?

• [ ] Yes
• [ ] No

Other information

This seems to solve the issue for us 👍

Hey! Maybe would be possible to address #1342 with this change? Or maybe it will fix it already?