feat: separate package for PackageManager util

[arpitBhalla]

Summary:

• Separated PackageManager into another package

Related rise-tools/rise-tools#161

Test Plan:

Checklist

• Documentation is up to date to reflect these changes.
• Follows commit message convention described in CONTRIBUTING.md

^ @grabbou

[TMisiukiewicz]

Thanks for working on this! In my opinion, in this PR we should focus only on extracting currently existing logic into separate package. IIRC pnpm still requires some tweaks to make it work with CLI, (check here) so to not block things, I'd remove pnpm part from this PR

[szymonrybczak]

LGTM, left few nits comments

[szymonrybczak]

@arpitBhalla can you take a look at failing tests? 🙏

[github-actions]

There hasn't been any activity on this pull request in the past 3 months, so it has been marked as stale and it will be closed automatically if no further activity occurs in the next 7 days.