revert invis spells to break all charm

http://everquest.allakhazam.com/db/item.html?item=1653

[12:49am] robregen: Because any invis spell breaks all charm spells. In other words, for enchanters and druids and necros, this is a quick way to break charm on a charmed pet, without having to mem invis.
[12:49am] robregen: And yes, even for non-animals, invis to animals breaks charm.
[12:50am] robregen: ar 23 2005 at 6:44 AM

For reference I modified the SetInvis function in a past commit to take a flag to set the invis state so invis vs undead/animals doesn't show them as invis:

https://github.com/cavedude00/Server/blob/677200192f338e3d4950738c78f2868dbd55b7b2/zone/mob.cpp#L446-L462