feat: add client reload on config change

[obadoraibu]

Thid pull request proposed as part of the homework for the course "designing the architecture of software systems". The ability to configure client updates when configuration files are changed is implemented. "Watcher" was used instead of "fsnotify" due to problems with the compatibility of the second with macos

[fatedier]

https://github.com/fatedier/frp/pull/3728#issuecomment-1789992965

This feature is not currently in the plan due to some concerns and it is not very perfect. For now, you can reload the configuration through the reload API after updating the configuration file.

[github-actions[bot]]

PRs go stale after 21d of inactivity. Stale PRs rot after an additional 7d of inactivity and eventually close.