Add admin command to give players effects

Currently, admins are able to use /cleareffects to get rid of all their effects and /rewardwellrested to give others the well rested buff, but they are not able to give other effects that are in game.

I think it would be useful to have a /addeffect command to give other players different effects, such as the homecave buff/debuff, and login debuff. Something like /addeffect CptFacepalm HomecaveBuff 60s to give a player the homecave buff for 60 seconds would be great to have.

Expanding /cleareffects to also be usable on other players would be a nice addition as well.