Update MkvInfoReader, Add MkvNode extensions

MkvToolnixWrapper/MkvInfo/Reader/MkvProperty.cs

@@ -0,0 +1,64 @@
+using System.Text;
+
+namespace MkvPropEditWrapper.MkvInfo.Reader;
+
+public class MkvProperty : MkvNode
+{
+    private static class KnownProperties
+    {
+        public const string TrackType = "Track type";
+        public const string TrackNumber = "Track number";
+        public const string FlagDefault = "\"Default track\" flag";
+        public const string FlagForced = "\"Forced display\" flag";
+        public const string Language = "Language";
+    }
+
+    public override NodeType NodeType => NodeType.Property;
+    public PropertyType PropertyType { get; }
+    public ReadOnlyMemory<char> Value { get; }
+
+    public MkvProperty(MkvNode? parent, ReadOnlyMemory<char> name, ReadOnlyMemory<char> value)
+        : base(parent, name)
+    {
+        Value = value;
+
+        PropertyType = FindPropertyType(name);
+    }
+
+    private static PropertyType FindPropertyType(ReadOnlyMemory<char> name)
+    {
+        var span = name.Span;
+        
+        if (span.SequenceEqual(KnownProperties.TrackType))
+        {
+            return PropertyType.TrackType;
+        }
+        
+        if (span.SequenceEqual(KnownProperties.TrackNumber))
+        {
+            return PropertyType.TrackNumber;
+        }
+
+        if (span.SequenceEqual(KnownProperties.FlagDefault))
+        {
+            return PropertyType.FlagDefault;
+        }
+
+        if (span.SequenceEqual(KnownProperties.FlagForced))
+        {
+            return PropertyType.FlagForced;
+        }
+
+        if (span.SequenceEqual(KnownProperties.Language))
+        {
+            return PropertyType.Language;
+        }
+
+        return PropertyType.Unknown;
+    }
+
+    protected override void AppendSelf(StringBuilder builder)
+    {
+        builder.AppendLine($"{new string('-', Depth)}> [{NodeType}] {Name}: {Value}");
+    }
+}