Unblank the sourceName field for group members being hit by an attacker

Letho2469

@ZOS_BrianWheeler: As far as I remember you are the one in charge for the combat API. As an addon author I fully understand that you blank out undesired fields that allow ppl to craft addons like damage meters and addons that circumvent game mechanics. There is still one thing that bothers me: You introduced the rule that combat events will only contain information if you are either the source or the target of that action, otherwise they only contain the used ability id. My request is simple, just as the title states I wish I could see all data when a group member is being the target of an NPC. Group members' actions against NPCs can be used for creating a dmg meter, yes, but I don't know why you blank the field if the action is coming from an NPC, targeted at a group member. That is no sensitive information. The blanked fields problem can be circumented by using map pings for transfering data from one client to another, anyway, so unblanking those fields would even save traffic.