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

app/controllers/statuses_controller.rb

@@ -1,11 +1,11 @@
 # frozen_string_literal: true
 
 class StatusesController < ApplicationController
+  include WebAppControllerConcern
   include StatusControllerConcern
   include SignatureAuthentication
   include Authorization
   include AccountOwnedConcern
-  include WebAppControllerConcern
 
   before_action :require_account_signature!, only: [:show, :activity], if: -> { request.format == :json && authorized_fetch_mode? }
   before_action :set_status