Improve vv /c/enthover and add keybind (#20127)

Content.Client/UserInterface/IEntityControl.cs

@@ -0,0 +1,10 @@
+namespace Content.Client.UserInterface;
+
+/// <summary>
+/// Simple interface that indicates that the given control is associated with some entity.
+/// This is primarily intended to be used with VV, so that you can easily open the VV window to examine an entity.
+/// </summary>
+public interface IEntityControl
+{
+    EntityUid? UiEntity { get; }
+}