Add scrollbar's in JournalLists and FolderLists

Pros: It's nice to know where we are in the list.
Cons: It makes the lagging in the list view far far more apparent.

lib/screens/folder_listing.dart

@@ -120,7 +120,7 @@ class _FolderListingScreenState extends State<FolderListingScreen> {
           if (selectedFolder != null) action,
         ],
       ),
-      body: treeView,
+      body: Scrollbar(child: treeView),
       drawer: AppDrawer(),
       floatingActionButton: CreateFolderButton(),
     );

lib/screens/journal_listing.dart

@@ -64,7 +64,7 @@ class JournalListingScreen extends StatelessWidget {
       floatingActionButton: createButton,
       body: Center(
         child: RefreshIndicator(
-            child: journalList,
+            child: Scrollbar(child: journalList),
             onRefresh: () async {
               try {
                 await container.syncNotes();