OnClothingItemContentsChanged no longer calls OnClothingChanged
Looks like it was doing this for recalculating protection from armour inserts, but this only needs to call SV_ClothingChanged
Fixes a bug where items moved to/from slot 7 of a backpack were being treated as equipping/unequipping a backpack. Also removes some redundant inventory server updates on every item moved to/from a piece of clothing