Function rewrite_api_host_to_vault 

fn rewrite_api_host_to_vault(url: &str) -> Option<String>

Rewrite a leading api. host label to vault. in a scheme://host[/path] URL, e.g. https://api.bitwarden.com -> https://vault.bitwarden.com. Returns None when the URL has no scheme or the host does not start with the api. label (so apiary.example.com is not rewritten).