fix: 🐛 Fix scrollbar for the sidebar in desktop client (#1076)

Fixed scroll bar always appearing in sidebar on macOS for desktop client
and sidebar not staying fixed in windows and linux

✅ Closes: ICU-4143

ui/desktop/app/styles/app.scss

@@ -39,22 +39,7 @@
 
   .rose-layout-sidebar-sidebar,
   .rose-layout-sidebar-body {
-    overflow-y: scroll;
-  }
-
-  &.layout-scroll {
-    .rose-layout-global-body {
-      overflow-y: auto;
-
-      main {
-        overflow: unset;
-      }
-    }
-
-    .rose-layout-sidebar-sidebar,
-    .rose-layout-sidebar-body {
-      overflow-y: unset;
-    }
+    overflow-y: auto;
   }
 }
 

ui/desktop/app/templates/application.hbs

@@ -1,9 +1,6 @@
 {{page-title (app-name)}}
 
-<Rose::Layout::Global
-  class='{{if this.showWindowActions ' layout-scroll'}}'
-  as |layout|
->
+<Rose::Layout::Global as |layout|>
 
   <layout.header>
     <Rose::Header