add VersionedSerialization + source generator

VersionedSerialization/IReader.cs

@@ -0,0 +1,22 @@
+using System.Collections.Immutable;
+
+namespace VersionedSerialization;
+
+public interface IReader
+{
+    bool Is32Bit { get; }
+
+    bool ReadBoolean();
+    long ReadNInt();
+    ulong ReadNUInt();
+    string ReadString();
+    ReadOnlySpan<byte> ReadBytes(int length);
+
+    T Read<T>() where T : unmanaged;
+    ImmutableArray<T> ReadArray<T>(long count) where T : unmanaged;
+
+    T ReadObject<T>(in StructVersion version = default) where T : IReadable, new();
+    ImmutableArray<T> ReadObjectArray<T>(long count, in StructVersion version = default) where T : IReadable, new();
+
+    public void Align(int alignment = 0);
+}