Add foundation

Toolkit.Foundation/NavigationContextAttribute.cs

@@ -0,0 +1,12 @@
+namespace Toolkit.Foundation;
+
+[AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
+public class NavigationContextAttribute : Attribute
+{
+    public NavigationContextAttribute(string name)
+    {
+        Name = name;
+    }
+
+    public string Name { get; }
+}