Adapt cursors for annotation interactions

- Reason: in conjunction with moving shapes [2038], to get a more
  consistent cursor behavior for movable elements.

Use 'move' cursor for movable annotation arrows

- Reason: in conjunction with moving shapes [2038], to get a more
  consistent cursor behavior for movable elements.

Author: rmoestl

src/components/annotations/draw.js

@@ -132,7 +132,7 @@ function drawRaw(gd, options, index, subplotId, xa, ya) {
 
     var annTextGroupInner = annTextGroup.append('g')
         .style('pointer-events', textEvents ? 'all' : null)
-        .call(setCursor, 'default')
+        .call(setCursor, 'pointer')
         .on('click', function() {
             gd._dragging = false;
 
@@ -533,6 +533,7 @@ function drawRaw(gd, options, index, subplotId, xa, ya) {
                 var arrowDrag = arrowGroup.append('path')
                     .classed('annotation-arrow', true)
                     .classed('anndrag', true)
+                    .classed('cursor-move', true)
                     .attr({
                         d: 'M3,3H-3V-3H3ZM0,0L' + (tailX - arrowDragHeadX) + ',' + (tailY - arrowDragHeadY),
                         transform: 'translate(' + arrowDragHeadX + ',' + arrowDragHeadY + ')'