Libraries

This change looks dramatic, but it's just separating out the already-split namespaces into separate top-level folders. In theory, every single one could be built into their own Nuget package. `SabreTools.Serialization` still builds the normal Nuget package that is used by all other projects and includes all namespaces.

SabreTools.Data.Models/Metadata/MetadataFile.cs

@@ -0,0 +1,25 @@
+
+namespace SabreTools.Data.Models.Metadata
+{
+    /// <summary>
+    /// Format-agnostic representation of a full metadata file
+    /// </summary>
+    public class MetadataFile : DictionaryBase
+    {
+        #region Keys
+
+        /// <remarks>Machine[]</remarks>
+        [NoFilter]
+        public const string MachineKey = "machine";
+
+        /// <remarks>Header</remarks>
+        [NoFilter]
+        public const string HeaderKey = "header";
+
+        /// <remarks>InfoSource</remarks>
+        [NoFilter]
+        public const string InfoSourceKey = "infosource";
+
+        #endregion
+    }
+}