[Messages] Add GM Status and Invulnerability Messages (#4266)

* [Messages] Add GM Status and Invulnerability Messages

* Update zoning.cpp

* Finalize.

* Update corpse.cpp

* Update message

---------

Co-authored-by: Akkadius <akkadius1@gmail.com>

zone/trading.cpp

@@ -814,6 +814,18 @@ void Client::FinishTrade(Mob* tradingWith, bool finalizer, void* event_entry, st
 									((is_pet && (!bagitem->IsQuestItem() || pets_can_take_quest_items) ||
 									!is_pet)))) {
 
+									if (GetGM()) {
+										const std::string& item_link = database.CreateItemLink(bagitem->ID);
+										Message(
+											Chat::White,
+											fmt::format(
+												"Your GM Flag allows you to give {} to {}.",
+												item_link,
+												GetTargetDescription(tradingWith)
+											).c_str()
+										);
+									}
+
 									auto loot_drop_entry = LootdropEntriesRepository::NewNpcEntity();
 									loot_drop_entry.equip_item = 1;
 									loot_drop_entry.item_charges = static_cast<int8>(baginst->GetCharges());