Plugin side toolbar design tweak

- Added new parameter to navigation buttons: priority.
- Ordered the navigation buttons by their priority and name in PluginToolbar.
- Added a maximum size to the navigation buttons to keep all their sizes
the same.
- Added new icons for the following plugins:
   - Account (login/logout)
   - Grand Exchange
   - Feed
   - Info
   - Kourend Library
   - Notes
   - Screenshot

runelite-client/src/main/java/net/runelite/client/util/SwingUtil.java

@@ -310,6 +310,7 @@ public class SwingUtil
 			: navigationButton.getIcon();
 
 		final JButton button = new JButton();
+		button.setMaximumSize(new Dimension(30, 30));
 		button.setName(navigationButton.getName());
 		button.setToolTipText(navigationButton.getTooltip());
 		button.setIcon(new ImageIcon(scaledImage));