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/accounts_controller.rb

@@ -9,7 +9,6 @@ class AccountsController < ApplicationController
 
   before_action :require_account_signature!, if: -> { request.format == :json && authorized_fetch_mode? }
   before_action :set_cache_headers
-  before_action :set_body_classes
 
   skip_around_action :set_locale, if: -> { [:json, :rss].include?(request.format&.to_sym) }
   skip_before_action :require_functional!, unless: :whitelist_mode?
@@ -18,24 +17,6 @@ class AccountsController < ApplicationController
     respond_to do |format|
       format.html do
         expires_in 0, public: true unless user_signed_in?
-
-        @pinned_statuses   = []
-        @endorsed_accounts = @account.endorsed_accounts.to_a.sample(4)
-        @featured_hashtags = @account.featured_tags.order(statuses_count: :desc)
-
-        if current_account && @account.blocking?(current_account)
-          @statuses = []
-          return
-        end
-
-        @pinned_statuses = cached_filtered_status_pins if show_pinned_statuses?
-        @statuses        = cached_filtered_status_page
-        @rss_url         = rss_url
-
-        unless @statuses.empty?
-          @older_url = older_url if @statuses.last.id > filtered_statuses.last.id
-          @newer_url = newer_url if @statuses.first.id < filtered_statuses.first.id
-        end
       end
 
       format.rss do
@@ -55,18 +36,6 @@ class AccountsController < ApplicationController
 
   private
 
-  def set_body_classes
-    @body_classes = 'with-modals'
-  end
-
-  def show_pinned_statuses?
-    [replies_requested?, media_requested?, tag_requested?, params[:max_id].present?, params[:min_id].present?].none?
-  end
-
-  def filtered_pinned_statuses
-    @account.pinned_statuses.where(visibility: [:public, :unlisted])
-  end
-
   def filtered_statuses
     default_statuses.tap do |statuses|
       statuses.merge!(hashtag_scope)    if tag_requested?
@@ -113,26 +82,6 @@ class AccountsController < ApplicationController
     end
   end
 
-  def older_url
-    pagination_url(max_id: @statuses.last.id)
-  end
-
-  def newer_url
-    pagination_url(min_id: @statuses.first.id)
-  end
-
-  def pagination_url(max_id: nil, min_id: nil)
-    if tag_requested?
-      short_account_tag_url(@account, params[:tag], max_id: max_id, min_id: min_id)
-    elsif media_requested?
-      short_account_media_url(@account, max_id: max_id, min_id: min_id)
-    elsif replies_requested?
-      short_account_with_replies_url(@account, max_id: max_id, min_id: min_id)
-    else
-      short_account_url(@account, max_id: max_id, min_id: min_id)
-    end
-  end
-
   def media_requested?
     request.path.split('.').first.end_with?('/media') && !tag_requested?
   end
@@ -145,13 +94,6 @@ class AccountsController < ApplicationController
     request.path.split('.').first.end_with?(Addressable::URI.parse("/tagged/#{params[:tag]}").normalize)
   end
 
-  def cached_filtered_status_pins
-    cache_collection(
-      filtered_pinned_statuses,
-      Status
-    )
-  end
-
   def cached_filtered_status_page
     cache_collection_paginated_by_id(
       filtered_statuses,