Add new overlay layer position

- Add new overlay layer position that draws right above overheads and HP
bars, what is perfect for game interfaces
- Make this new layer use UNDER_WIDGETS layer position, and move the
before layer position to ABOVE_SURFACE

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>

runelite-client/src/main/java/net/runelite/client/callback/Hooks.java

@@ -24,6 +24,7 @@
  */
 package net.runelite.client.callback;
 
+import net.runelite.api.TextureProvider;
 import net.runelite.api.events.GameTick;
 import net.runelite.api.events.ProjectileMoved;
 import net.runelite.api.events.MenuEntryAdded;
@@ -127,6 +128,22 @@ public class Hooks
 		BufferedImage image = (BufferedImage) bufferProvider.getImage();
 		Graphics2D graphics2d = (Graphics2D) image.getGraphics();
 
+		try
+		{
+			renderer.render(graphics2d, OverlayLayer.ABOVE_SCENE);
+		}
+		catch (Exception ex)
+		{
+			log.warn("Error during overlay rendering", ex);
+		}
+	}
+
+	public static void drawAboveOverheads(TextureProvider textureProvider, int var1)
+	{
+		MainBufferProvider bufferProvider = (MainBufferProvider) client.getBufferProvider();
+		BufferedImage image = (BufferedImage) bufferProvider.getImage();
+		Graphics2D graphics2d = (Graphics2D) image.getGraphics();
+
 		try
 		{
 			renderer.render(graphics2d, OverlayLayer.UNDER_WIDGETS);

runelite-client/src/main/java/net/runelite/client/ui/overlay/OverlayLayer.java

@@ -27,17 +27,22 @@ package net.runelite.client.ui.overlay;
 public enum OverlayLayer
 {
 	/**
-	 * Render overlay above all game elements
+	 * Render right above the scene (that contains actors and the surface)
 	 */
-	ALWAYS_ON_TOP,
+	ABOVE_SCENE,
 
 	/**
-	 * Render under all interfaces
+	 * Render under all interfaces, but above overheads
 	 */
 	UNDER_WIDGETS,
 
 	/**
 	 * Render under the right-click menu
 	 */
-	ABOVE_WIDGETS
+	ABOVE_WIDGETS,
+
+	/**
+	 * Render overlay above all game elements
+	 */
+	ALWAYS_ON_TOP,
 }