[Commands] Cleanup #aggrozone Command. (#1798)

- Cleanup message and logic.
- Add the ability to aggro the zone on your target if you have one.

zone/gm_commands/aggrozone.cpp

@@ -2,18 +2,30 @@
 
 void command_aggrozone(Client *c, const Seperator *sep)
 {
-	if (!c) {
-		return;
+	Mob *target = c;
+	if (c->GetTarget()) {
+		target = c->GetTarget();
 	}
 
-	Mob *m = c->CastToMob();
-
-	if (!m) {
-		return;
+	uint32 hate = 0;
+	if (sep->IsNumber(1)) {
+		hate = std::stoul(sep->arg[1]);
 	}
 
-	uint32 hate = atoi(sep->arg[1]); //should default to 0 if we don't enter anything
-	entity_list.AggroZone(m, hate);
-	c->Message(Chat::White, "Train to you! Last chance to go invulnerable...");
+	entity_list.AggroZone(target, hate);
+	c->Message(
+		Chat::White,
+		fmt::format(
+			"Aggroing zone on {}.",
+			(
+				c == target ?
+				"yourself" :
+				fmt::format(
+					"{} ({})",
+					target->GetCleanName(),
+					target->GetID()
+				)
+			)
+		).c_str()
+	);
 }
-