2D overlay : EmulGL and native should have the same code when dealing with HiDPI

[jzy3d]

Currently, some specific code is required when handling 2D overlays with JOGL (native) and EmulGL charts.

IViewOverlay impl	JOGL : AWTNativeViewOverlay)	EmulGL : EmulGLViewOverlay
Similar	Applies pixel scale to G2D	Applies pixel scale to G2D
Different	canvas.getRendererHeight() is pixel scaled	canvas.getRendererHeight() is not pixel scaled

This result in lot of code area where we use canvas.isNative() to apply different formulae for the layout in EmulGL or Native (e.g. View2DLayout).

Code would be simpler and more readable if EmulGLCanvas could return a scaled renderer height/width.

[jzy3d]

Another way of dealing with HiDPI for Windows would be

      setLayout(new BorderLayout() {
          @Override
          public void layoutContainer(Container target) {
              synchronized (target.getTreeLock()) {
                  Insets insets = target.getInsets();
                  int top = insets.top;
                  int bottom = target.getHeight() - insets.bottom;
                  int left = insets.left;
                  int right = target.getWidth() - insets.right;

                  Graphics graphics = getGraphics();
                  AffineTransform transform = ((Graphics2D) graphics).getTransform();
                  double scaleX = transform.getScaleX();
                  double scaleY = transform.getScaleY();

                  int width = right - left;
                  int height = bottom - top;
                  width *= scaleX;
                  height *= scaleY;

                  renWin.setBounds(left, top, width, height);
              }
          }
      });