media assets: redesign show page.

Redesign the media assets show page to:

* Include sidebar with AI tags and image metadata.
* Include next and previous image buttons.
* Make the image use 100% of the available screen space and to scroll with the window.

app/views/uploads/_single_asset_upload.html.erb

@@ -23,7 +23,7 @@
   <div id="client-errors" class="error-messages ui-state-error ui-corner-all" style="display:none"></div>
 
   <div id="upload-image">
-    <%= render MediaAssetComponent.new(media_asset: media_asset) %>
+    <%= render MediaAssetComponent.new(media_asset: media_asset, current_user: CurrentUser.user) %>
 
     <p>
       <strong>Size</strong>