[Tizen][Runtime]Implement screen-orientation feature.

According to Tizen core spec feature XWALK-1491, add a setting attribute "screen-orientation" in Tizen configure file.
This attribute controls whether screen orietation is locked or not. Its value can be one of "portrait", "landscape", "auto-rotation", and the default value should be "portrait".
if (!info)
  return blink::WebScreenOrientationLockDefault;
switch(info->screen_orientation()) {
case blink::WebScreenOrientationLockPortrait:
  return blink::WebScreenOrientationLockPortrait;
case ..
default:
NOTREACHED;
}