feat(thumbnails) Use cornerstone.renderToCanvas for Series Thumbnails

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

@@ -1,10 +1,16 @@
 <template name="imageThumbnail">
     <div class="imageThumbnail">
-        <div class="imageThumbnailCanvas"></div>
-        <div class="imageThumbnailLoadingIndicator thumbnailLoadingIndicator">
+        <div class="imageThumbnailCanvas">
+            <img class="static-image"/>
+        </div>
+        <div class="imageThumbnailLoadingIndicator
+                    thumbnailLoadingIndicator
+                    {{ #if isLoading }}d-block{{/if}}">
             <p>Loading {{percentComplete}}</p>
         </div>
-        <div class="imageThumbnailErrorLoadingIndicator thumbnailLoadingIndicator">
+        <div class="imageThumbnailErrorLoadingIndicator
+                    thumbnailLoadingIndicator
+                    {{ #if hasLoadingError }}d-block{{/if}}">
             <p>Error</p>
         </div>
         {{#if showStackLoadingProgressBar}}