feature/add-write-read-tree-entry

[mahis1067]

Summary

• Created ObjectStore.write_tree and read_tree
• Created helper methods to validate tree format
• Test functions

Validation

• scripts/quality-check.sh
• Manual testing, if applicable:

Checklist

• The change is focused and easy to review.
• Tests were added or updated for behavior changes.
• Documentation was updated for user-facing or setup changes.
• No secrets, generated artifacts, or local-only files are included.

Notes for Reviewers

• Pytest parameters are manually written to check multiple cases of incorrectly formatted tree enteries and hashes