update finance mocks

- notice I added a legend to finance_style, so we test ohlc legend drawing
- also notice that I changed ohlc line drawing to not overdraw. Directions were chosen to optimize dashes:
  - the ticks are drawn starting from the outside toward the middle
  - the main line is drawn top-to-bottom, so in principle you might not actually see the low value,
    but that was the case before anyway, there's really no way around this with dashes...

Author: alexcjohnson

test/image/baselines/candlestick_double-y-axis.png

@@ -268,7 +268,7 @@
       "calendar": "islamic",
       "title": "Islamic dates"
     },
-    "showlegend": false,
+    "showlegend": true,
     "height": 450,
     "width": 1100,
     "autosize": true