OHIF-79: Study Browser side panel (#1614)

* Initial code changes for StudyBrowser

* StudyItem component basic strucure

* Adding new icon

* Updates to get StudyItem working

* Small fix on side panel open header

* Adding new icons

* Thumbnail List

* ThumbnailSR WIP

* Thumanil WIP

* Export new components into ohif/ui

* Updates on style

* Update ThumbnailSR style

* Margin updates

* MAke it scrollable

* Make it scrollable

* Style updates

* Fixing tooltip

* Tunning the mock data and testing scenarios

* Update mock data

* make all studies collapsed

* small fix on tooltip

* Removing empty mdx files

* Updating viewer docz page

* Style updates

* Update button font-size

* Fix: Make cancel button only visible on hover

* Fixing callouts

* Fix eslint

platform/ui/src/components/Thumbnail/index.js

@@ -0,0 +1,2 @@
+import Thumbnail from './Thumbnail';
+export default Thumbnail;