* Allow configuring the number of days to expire documents
* Update server tests about server data
* Update test_cleanup for testing a different expiry value
* Remove unnecessary Arc<> while passing expiry_days to cleaner
* Rename `ServerData` to `ServerConfig`
* Update tests to rename the `ServerData`
* Update rustpad-server/tests/cleanup.rs
Co-authored-by: Eric Zhang <ekzhang1@gmail.com>