Loads a player with a randomly selected commander from a specified file.
* This function reads a file ('User/commander/commander.txt') that contains a list of potential commander IDs or names.
* It selects one randomly to be used as the player's commander. If the file doesn't exist, or no valid commanders are found, a default commander ID (670972) is used.
* Can read the commander name and a multiverseID
* Lines that start with '#' are ignored