Players in vanish can still be messaged by manually typing their name

[vLuckyyy]

Currently, when using the /msg command, vanished players are correctly excluded from the tab-completion list. However, if a player manually types the name of a vanished player, the message still goes through.

This is a privacy issue and should be fixed by modifying the PlayerArgument parser logic to reject vanished players. A vanish check must be added in the parse method of the PlayerArgument class to prevent this.