Multiple Ui improvements (#7029)

* PLT-7119 - Updating headings on compact view

* PLT-7103 - Removing line below channel intro

* PLT-7112 - Fixing system console banner

* PLT-7144 - Adding ellipsis to system console boxes

* PLT-7181 - Changing channel header opacity

* PLT-6899 - Updating unread bar

* Updating margin for new messages indicator

webapp/components/sidebar.jsx

@@ -745,15 +745,15 @@ export default class Sidebar extends React.Component {
 
         const above = (
             <FormattedMessage
-                id='sidebar.unreadAbove'
-                defaultMessage='Unread post(s) above'
+                id='sidebar.unreads'
+                defaultMessage='More unreads'
             />
         );
 
         const below = (
             <FormattedMessage
-                id='sidebar.unreadBelow'
-                defaultMessage='Unread post(s) below'
+                id='sidebar.unreads'
+                defaultMessage='More unreads'
             />
         );