Ladybird+LibWebView: Move APIs which only repaint to LibWebView

We can easily add hooks to notify the browsers of these events if any
implementation-specific handling is needed in the future, but for now,
these only repaint the client, which we can do in ViewImplementation.

Userland/Libraries/LibWebView/ViewImplementation.cpp

@@ -70,6 +70,16 @@ void ViewImplementation::server_did_paint(Badge<WebContentClient>, i32 bitmap_id
     }
 }
 
+void ViewImplementation::server_did_invalidate_content_rect(Badge<WebContentClient>, Gfx::IntRect)
+{
+    request_repaint();
+}
+
+void ViewImplementation::server_did_change_selection(Badge<WebContentClient>)
+{
+    request_repaint();
+}
+
 void ViewImplementation::load(AK::URL const& url)
 {
     m_url = url;