Finds a plugin by its order in the list from the "plugins list" server "sm" command. You should not use this function to loop through all plugins, use the iterator instead. Looping through all plugins using this native is O(n^2), whereas using the iterator is O(n).
Handle FindPluginByNumber(int order_num)
Number of the plugin as it appears in "sm plugins list".
Plugin Handle on success, INVALID_HANDLE if no plugin matches the given number.