[GM Commands] Split GM Commands Into Separate Files (#1766)

* Split GM commands into their own files

* Code cleanup

zone/gm_commands/distance.cpp

@@ -0,0 +1,23 @@
+#include "../client.h"
+
+void command_distance(Client *c, const Seperator *sep)
+{
+	if (c->GetTarget()) {
+		Mob *target = c->GetTarget();
+		if (c != target) {
+			c->Message(
+				Chat::White,
+				fmt::format(
+					"{} ({}) is {:.2f} units from you.",
+					target->GetCleanName(),
+					target->GetID(),
+					Distance(
+						c->GetPosition(),
+						target->GetPosition()
+					)
+				).c_str()
+			);
+		}
+	}
+}
+