Add Enchanted Sigil of Flowing Waters

[kayla-glick]

https://www.wowhead.com/classic/item=228978/enchanted-sigil-flowing-waters

This item provides a full raid buff of 30 SP and AP. It cannot be used at the same time as other sigils.

Add this as a Misc raid buff option only shown when the player is not an enchanter

If the player is an enchanter, show it as an option in the Enchanting Sigils picker