feat(questions): list and restore removed games

Add a "Removed games" section on the questions page and an Undo
toast after removing a manual game (#39).

public/i18n/en.json

@@ -540,10 +540,11 @@
     "PLATFORM": "Platform",
     "HOURS": "Hours played",
     "REMOVE": "Remove from library",
-    "REMOVE_CONFIRM": "Remove this game with its status, rating and notes?",
+    "REMOVE_CONFIRM": "Remove this game? You can restore it under Questions.",
     "REMOVE_YES": "Yes, remove",
     "REMOVE_NO": "Cancel",
     "REMOVED": "Game removed.",
+    "UNDO": "Undo",
     "NO_ACHIEVEMENTS": "Achievements and trophies exist only for games from Steam or PlayStation.",
     "SELECT": "Select {{name}}",
     "SELECTED": "{{count}} selected",
@@ -1341,6 +1342,12 @@
       "STATUS": "Status changes"
     }
   },
+  "REMOVED_GAMES": {
+    "TITLE_COUNT": "Removed games ({{count}})",
+    "RESTORE": "Restore",
+    "RESTORED": "Game restored.",
+    "HINT": "Restored games keep their status, rating and notes."
+  },
   "QUESTIONS": {
     "TITLE": "Questions",
     "TITLE_COUNT": "Questions ({{count}})",