SYS-379: Add verifyUnseen test

[muni-corn]

Depends on #244 . Will keep as a draft until #244 is merged.

[github-actions]

PR Reviewer Guide 🔍

⏱️ Estimated effort to review: 4 🔵🔵🔵🔵⚪

🧪 PR contains tests

🔒 No security concerns identified

⚡ Key issues to review Code Duplication The validate.ts file contains multiple instances of similar error objects being created, such as BAD_STRUCTURE_ERROR, BAD_NODE_INFO_STRUCTURE_ERROR, and BAD_SIGNATURE_STRUCTURE_ERROR. Consider refactoring these into a more generic function or a factory pattern to reduce code duplication and improve maintainability. Complex Logic The function validateJoinRequest and other validation functions in validate.ts are quite complex and perform multiple checks. Consider breaking these down into smaller, more manageable functions to improve readability and maintainability. Global State The logging setup in logging.ts uses a global logger instance p2pLogger. Using global state can lead to issues with maintainability and testing. Consider passing the logger as a dependency where needed.