Slider: Use cursor: pointer on handles

Fixes #9371
Closes jquerygh-1800

Author: scottgonzalez

themes/base/slider.css

@@ -17,7 +17,7 @@
 	z-index: 2;
 	width: 1.2em;
 	height: 1.2em;
-	cursor: default;
+	cursor: pointer;
 	-ms-touch-action: none;
 	touch-action: none;
 }