Function get_lockout_message_if_locked 

pub fn get_lockout_message_if_locked(
    username: &str,
    app: &AppState,
) -> Option<String>

What: Check if user is locked out and return lockout message if so.

Inputs:

• username: Username to check.
• app: Application state for translations.

Output:

• Some(message) if user is locked out, None otherwise.

Details:

• Checks faillock status and returns formatted lockout message if locked.
• Returns None if not locked or if check fails.
• Uses translations from AppState.