feat(thumbnails) Use cornerstone.renderToCanvas for Series Thumbnails

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

@@ -1,4 +1,4 @@
-@import "{ohif:design}/app"
+@require '{ohif:design}/app'
 
 .thumbnailEntry.active .imageThumbnail
   theme('border-color', '$activeColor')
@@ -47,6 +47,9 @@
   margin: auto
   position: absolute
 
+  &.d-block
+    display: block;
+
   p
     text-align: center
     font-size: 10pt