Add top right + orient=v test cases

Author: 28raining

src/components/legend/draw.js

@@ -668,7 +668,7 @@ function computeTextDimensions(g, gd, legendObj, aTitle) {
             } else if(legendObj.title.side === 'top center') {
                 if(legendObj._width) titleOffset = 0.5 * (legendObj._width - 2 * bw - 2 * constants.titlePad - width);
             } else if(legendObj.title.side === 'top right') {
-                if(legendObj._width) titleOffset = legendObj._width - bw - constants.titlePad - width;
+                if(legendObj._width) titleOffset = legendObj._width - 2 * bw - constants.titlePad - width;
             }
 
             svgTextUtils.positionText(textEl,

test/image/baselines/legend_horizontal_autowrap.png

@@ -547,7 +547,8 @@
         "size": 11.9552
       },
       "y": -0.4,
-      "orientation": "h"
+      "orientation": "h",
+      "title": { "text": "Legend Title", "side": "top right" }
     },
     "hovermode": "closest",
     "width": 680,

test/image/baselines/legend_itemwidth_dashline.png

@@ -39,7 +39,8 @@
   ],
   "layout": {
     "legend": {
-      "itemwidth": 60
+      "itemwidth": 60,
+      "title": { "text": "Title", "side": "top center" }
     }
   }
 }