fix: 🐛 Fix ghost shadow on thumb (#1113)

* fix: 🐛 Fix ghost shadow on thumb

Updated react-dnd package for the lates. Refactored thumbnail component

Closes: 1087

* feat: 🎸 Code review

Set flex instead of float. Add cypress tag to thumb container

* feat: 🎸 Code review. Revised style when no description

platform/ui/src/components/studyBrowser/StudyBrowser.styl

@@ -1,4 +1,4 @@
-.StudyBrowser
+.study-browser
   float: left
   height: 100%
   width: 100%
@@ -22,7 +22,7 @@
     &::-webkit-scrollbar
       display: none
 
-    .ThumbnailEntryContainer
+    .thumbnail-container
       margin: 0 auto;
       padding-bottom: 1.5rem;