ui: Rename "All messages" to "Combined feed"

Fixes: zulip#5832

Author: chrisbobbe

src/title/TitleSpecial.js

@@ -8,7 +8,7 @@ import { Icon } from '../common/Icons';
 import styles from '../styles';
 
 const specials = {
-  home: { name: 'All messages', icon: 'globe' },
+  home: { name: 'Combined feed', icon: 'globe' },
   private: { name: 'Direct messages', icon: 'mail' },
   starred: { name: 'Starred', icon: 'star' },
   mentioned: { name: 'Mentions', icon: 'at-sign' },

static/translations/messages_en.json

@@ -134,7 +134,7 @@
   "Failed to connect to server: {realm}": "Failed to connect to server: {realm}",
   "{_}": "{_}",
   "Home": "Home",
-  "All messages": "All messages",
+  "Combined feed": "Combined feed",
   "Direct messages": "Direct messages",
   "Starred": "Starred",
   "Mentions": "Mentions",