WIP: Item counts

Toolkit.Foundation/Count.cs

@@ -0,0 +1,10 @@
+namespace Toolkit.Foundation;
+
+public record Count
+{
+    public static CountEventArgs<TSender> As<TSender>(TSender sender) =>
+        new(sender);
+
+    public static CountEventArgs<TSender> As<TSender>() where TSender : new() =>
+        new(new TSender());
+}

Toolkit.Foundation/CountEventArgs.cs

@@ -0,0 +1,3 @@
+namespace Toolkit.Foundation;
+
+public record CountEventArgs<TSender>(TSender Sender);

Toolkit.Foundation/QueryEventArgs.cs

@@ -1,3 +1,3 @@
 namespace Toolkit.Foundation;
 
-public record QueryEventArgs<TValue>(TValue Value);
+public record QueryEventArgs<TSender>(TSender Sender);