Core/Spells: SpellAttr8 fixups - use creator instead of owner for SPELL_ATTR8_ONLY_TARGET_IF_SAME_CREATOR and removed cast time requirement for channelled spell predicted healing

Port From (https://github.com/TrinityCore/TrinityCore/commit/930a08fe03a033a6bb30fb8c94a8490c4b77fe91)

Source/Game/Entities/Conversation.cs

@@ -341,8 +341,8 @@ namespace Game.Entities
         TimeSpan GetDuration() { return _duration; }
         public uint GetTextureKitId() { return _textureKitId; }
 
-        public ObjectGuid GetCreatorGuid() { return _creatorGuid; }
-        public override ObjectGuid GetOwnerGUID() { return GetCreatorGuid(); }
+        public override ObjectGuid GetCreatorGUID() { return _creatorGuid; }
+        public override ObjectGuid GetOwnerGUID() { return GetCreatorGUID(); }
         public override uint GetFaction() { return 0; }
 
         public override float GetStationaryX() { return _stationaryPosition.GetPositionX(); }