Port metadata functionality from ST

SabreTools.Metadata.DatItems/Source.cs

@@ -0,0 +1,41 @@
+using System;
+
+#pragma warning disable IDE0290 // Use primary constructor
+namespace SabreTools.Metadata.DatItems
+{
+    /// <summary>
+    /// Source information wrapper
+    /// </summary>
+    public class Source : ICloneable
+    {
+        /// <summary>
+        /// Source index
+        /// </summary>
+        public readonly int Index;
+
+        /// <summary>
+        /// Source name
+        /// </summary>
+        public readonly string? Name;
+
+        /// <summary>
+        /// Constructor
+        /// </summary>
+        /// <param name="id">Source ID</param>
+        /// <param name="source">Source name, optional</param>
+        public Source(int id, string? source = null)
+        {
+            Index = id;
+            Name = source;
+        }
+
+        #region Cloning
+
+        /// <summary>
+        /// Clone the current object
+        /// </summary>
+        public object Clone() => new Source(Index, Name);
+
+        #endregion
+    }
+}