[Glitch] Change dismissed banners to be stored server-side

Port 7faa27e17d to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/reducers/settings.js

@@ -110,6 +110,15 @@ const initialState = ImmutableMap({
       body: '',
     }),
   }),
+
+  dismissed_banners: ImmutableMap({
+    'public_timeline': false,
+    'community_timeline': false,
+    'home.explore_prompt': false,
+    'explore/links': false,
+    'explore/statuses': false,
+    'explore/tags': false,
+  }),
 });
 
 const defaultColumns = fromJS([