[Merchants] Convert Clear/Delete/Save of Temporary Merchant Lists to Repositories (#3945)

* [Merchants] Convert Clear/Delete/Save of Temporary Merchant Lists to Repositories

- Convert `ClearMerchantTemp()`, `DeleteMerchantTemp()`, and `SaveMerchantTemp()` to repositories.

* Update merchantlist_temp_repository.h

common/repositories/merchantlist_temp_repository.h

@@ -44,7 +44,15 @@ public:
      */
 
 	// Custom extended repository methods here
-
+	static void ClearTemporaryMerchantLists(Database& db)
+	{
+		db.QueryDatabase(
+			fmt::format(
+				"TRUNCATE {}",
+				TableName()
+			)
+		);
+	}
 };
 
 #endif //EQEMU_MERCHANTLIST_TEMP_REPOSITORY_H