Add foundation

Toolkit.Foundation/ComponentHostCollection.cs

@@ -0,0 +1,21 @@
+using System.Collections;
+
+namespace Toolkit.Foundation;
+
+public class ComponentHostCollection :
+   IComponentHostCollection
+
+{
+    private readonly List<IComponentHost> hosts = [];
+
+    public void Add(IComponentHost host)
+    {
+        hosts.Add(host);
+    }
+
+    public IEnumerator<IComponentHost> GetEnumerator() =>
+        hosts.GetEnumerator();
+
+    IEnumerator IEnumerable.GetEnumerator() =>
+        hosts.GetEnumerator();
+}