[Glitch] Implement adding a user to a list from their profile

Port bb5558de62 to glitch-soc

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

@@ -26,6 +26,7 @@ import height_cache from './height_cache';
 import custom_emojis from './custom_emojis';
 import lists from './lists';
 import listEditor from './list_editor';
+import listAdder from './list_adder';
 import filters from './filters';
 import pinnedAccountsEditor from './pinned_accounts_editor';
 
@@ -57,6 +58,7 @@ const reducers = {
   custom_emojis,
   lists,
   listEditor,
+  listAdder,
   filters,
   pinnedAccountsEditor,
 };