Increase default window size to 720p

Now that the content is centered, it actually makes sense to use bigger
windows more suitable for modern screens.

client/src/main/java/org/moparforia/client/Game.java

@@ -23,7 +23,7 @@ public Game(JFrame frame, String server, int port, String lang, String username,
         game.init();
         game.start();
         frame.add(game);
-        frame.setSize(WIDTH + 20, HEIGHT + 40);
+        frame.setSize(1280, 720);
         frame.setResizable(true);
         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         frame.setVisible(true);