Remove UI code and icons nothing uses

TextureButton, ClickableTexture, Text, Notification and the FadeOut and
SlideX animations only Notification used, Utils.getOrNull and the
commented-out notify, Element.duration, the 17 PNG icons the Lucide SVGs
replaced, and the Textures constants for them and for files that don't
exist.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/main/java/org/saturnclient/ui/Utils.java

@@ -1,7 +1,5 @@
 package org.saturnclient.ui;
 
-import java.util.List;
-
 import org.saturnclient.common.provider.GLFWProvider;
 
 public class Utils {
@@ -64,18 +62,4 @@ public class Utils {
         }
         return builder.toString();
     }
-
-    public static <T> T getOrNull(List<T> list, int index) {
-        return (index >= 0 && index < list.size()) ? list.get(index) : null;
-    }
-
-    // public static void notify(NotificationKind kind, String title, String toast)
-    // {
-    // if (SaturnClient.client.currentScreen instanceof SaturnScreen) {
-    // ((SaturnScreen) SaturnClient.client.currentScreen)
-    // .draw(new Notification(SaturnClient.client.currentScreen.width,
-    // SaturnClient.client.currentScreen.height, kind,
-    // title, toast));
-    // }
-    // }
 }