Added hotkey support to viewerbase

Packages/viewerbase/client/components/studyBrowser/imageThumbnail/imageThumbnail.styl

@@ -0,0 +1,23 @@
+.imageThumbnail
+  width: 90px
+  height: 90px
+  background-color: black
+  margin: 0 auto
+  position: relative
+  
+.thumbnailLoadingIndicator
+  display: none
+  pointer-events: none
+  color: #f8a13f
+  height: 20px
+  width: 100%
+  top: 0
+  left: 0
+  right: 0
+  bottom: 0
+  margin: auto
+  position: absolute
+  
+  p
+    text-align: center
+    font-size: 10pt