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

* Split GM commands into their own files

* Code cleanup

zone/gm_commands/showzonegloballoot.cpp

@@ -0,0 +1,13 @@
+#include "../client.h"
+
+void command_showzonegloballoot(Client *c, const Seperator *sep)
+{
+	c->Message(
+		Chat::White,
+		"GlobalLoot for %s (%d:%d)",
+		zone->GetShortName(),
+		zone->GetZoneID(),
+		zone->GetInstanceVersion());
+	zone->ShowZoneGlobalLoot(c);
+}
+