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/DVD/ProgramChainTableEntry.cs

@@ -0,0 +1,30 @@
+using System.Runtime.InteropServices;
+
+namespace SabreTools.Data.Models.DVD
+{
+    /// <see href="https://dvd.sourceforge.net/dvdinfo/ifo_vmg.html"/>
+    [StructLayout(LayoutKind.Sequential)]
+    public sealed class ProgramChainTableEntry
+    {
+        /// <summary>
+        /// PGC category
+        /// </summary>
+        [MarshalAs(UnmanagedType.U1)]
+        public ProgramChainCategory Category;
+
+        /// <summary>
+        /// Unknown
+        /// </summary>
+        public byte Unknown;
+
+        /// <summary>
+        /// Parental management mask
+        /// </summary>
+        public ushort ParentalManagementMask;
+
+        /// <summary>
+        /// Offset to VMGM_PGC, relative to VMGM_LU
+        /// </summary>
+        public uint Offset;
+    }
+}