SYS-381: Add validateJoinRequestTimestamp 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 Complexity The validate.ts file contains a large amount of validation logic which could be simplified or broken down into smaller, more manageable functions or modules. This would improve maintainability and readability. Duplicate Code There are multiple instances of similar logging and event counting code that could be refactored into a single function to reduce duplication and improve maintainability. Error Handling The error handling in asynchronous operations could be improved by adding more specific error messages or handling specific types of errors differently to provide more context in the logs.