[Commands] Consolidate #show commands into a singular #show command (#3478)

* [Cleanup] Consolidate #show commands into a singular #show command

# Notes
- All `#show` commands like `#showbuffs` are now subcommands of `#show`.
- All aliases like `#showbuffs` still function.

* Push up progress.

* Final push.

* Cleanup.

* Update ip_lookup.cpp

* emotes not emote

* Cleanup

* Update servertalk.h

* Update show.cpp

* Fix

* Final push.

* #aggro

* #who

zone/gm_commands/show/distance.cpp

@@ -0,0 +1,23 @@
+#include "../../client.h"
+
+void ShowDistance(Client *c, const Seperator *sep)
+{
+	if (!c->GetTarget() || c->GetTarget() == c) {
+		c->Message(Chat::White, "You must have a target to use this command.");
+		return;
+	}
+
+	const auto t = c->GetTarget();
+
+	c->Message(
+		Chat::White,
+		fmt::format(
+			"{} is {:.2f} units from you.",
+			c->GetTargetDescription(t),
+			Distance(
+				c->GetPosition(),
+				t->GetPosition()
+			)
+		).c_str()
+	);
+}