Start adding currently-unused models

SabreTools.Models/Listxml/Port.cs

@@ -0,0 +1,15 @@
+using System.Xml;
+using System.Xml.Serialization;
+
+namespace SabreTools.Models.Listxml
+{
+    [XmlRoot("port")]
+    public class Port
+    {
+        [XmlAttribute("tag")]
+        public string Tag { get; set; }
+
+        [XmlElement("analog")]
+        public Analog[]? Analog { get; set; }
+    }
+}