[Bug Fix] Fix #set faction/#setfaction Command (#3575)

# Notes
- This was an oversight on my part in `#set` command consolidation.

zone/gm_commands/set/faction.cpp

@@ -0,0 +1,54 @@
+#include "../../client.h"
+
+void SetFaction(Client *c, const Seperator *sep)
+{
+	const auto arguments = sep->argnum;
+	if (arguments < 2 || !sep->IsNumber(2)) {
+		c->Message(Chat::White, "Usage: #set faction [Faction ID]");
+		return;
+	}
+
+	if (
+		!c->GetTarget() ||
+		(
+			c->GetTarget() &&
+			c->GetTarget()->IsClient()
+		)
+	) {
+		c->Message(Chat::White, "You must target an NPC to use this command.");
+		return;
+	}
+
+	NPC* t = c->GetTarget()->CastToNPC();
+
+	const uint32 npc_id     = t->GetNPCTypeID();
+	const int    faction_id = Strings::ToInt(sep->arg[2]);
+
+	const std::string& faction_name = content_db.GetFactionName(faction_id);
+
+	if (faction_name.empty()) {
+		c->Message(
+			Chat::White,
+			"Invalid Faction ID, please specify a valid Faction ID."
+		);
+		return;
+	}
+
+	c->Message(
+		Chat::White,
+		fmt::format(
+			"Faction Changed | Name: {} ({}) Faction: {} ({}).",
+			t->GetCleanName(),
+			npc_id,
+			content_db.GetFactionName(faction_id),
+			faction_id
+		).c_str()
+	);
+
+	const std::string &query = fmt::format(
+		"UPDATE npc_types SET npc_faction_id = {} WHERE id = {}",
+		faction_id,
+		npc_id
+	);
+	content_db.QueryDatabase(query);
+}