Public gallery improvements (#409)

- [x] Don't show extension in name field for publish
- [x] Open "Your published work" tab after publishing
- [x] Continue showing dialog for Report Abuse status
- [x] For showing COC in Public Gallery tab show backdrop of thumbnails
- [x] Liked -> My Favorites & Your published work -> My published work

src/Explorer/Panes/__snapshots__/PublishNotebookPaneComponent.test.tsx.snap

@@ -25,7 +25,7 @@ exports[`PublishNotebookPaneComponent renders 1`] = `
     <StackItem>
       <StyledTextFieldBase
         ariaLabel="Name"
-        defaultValue="SampleNotebook.ipynb"
+        defaultValue="SampleNotebook"
         label="Name"
         onChange={[Function]}
         required={true}