Change public accounts pages to mount the web UI (#19319)

* Change public accounts pages to mount the web UI

* Fix handling of remote usernames in routes

- When logged in, serve web app
- When logged out, redirect to permalink
- Fix `app-body` class not being set sometimes due to name conflict

* Fix missing `multiColumn` prop

* Fix failing test

* Use `discoverable` attribute to control indexing directives

* Fix `<ColumnLoading />` not using `multiColumn`

* Add `noindex` to accounts in REST API

* Change noindex directive to not be rendered by default before a route is mounted

* Add loading indicator for detailed status in web UI

* Fix missing indicator appearing while account is loading in web UI

spec/controllers/authorize_interactions_controller_spec.rb

@@ -39,7 +39,7 @@ describe AuthorizeInteractionsController do
       end
 
       it 'sets resource from url' do
-        account = Account.new
+        account = Fabricate(:account)
         service = double
         allow(ResolveURLService).to receive(:new).and_return(service)
         allow(service).to receive(:call).with('http://example.com').and_return(account)
@@ -51,7 +51,7 @@ describe AuthorizeInteractionsController do
       end
 
       it 'sets resource from acct uri' do
-        account = Account.new
+        account = Fabricate(:account)
         service = double
         allow(ResolveAccountService).to receive(:new).and_return(service)
         allow(service).to receive(:call).with('found@hostname').and_return(account)