Function search_public_chat 

pub async fn search_public_chat(
    username: String,
    client_id: i32,
) -> Result<Chat, Error>

Searches a public chat by its username. Currently, only private chats, supergroups and channels can be public. Returns the chat if found; otherwise, an error is returned

Arguments

• username - Username to be resolved
• client_id - The client id to send the request to