Optimize follower_accounts and following_accounts (#2820)

app/controllers/follower_accounts_controller.rb

@@ -4,6 +4,6 @@ class FollowerAccountsController < ApplicationController
   include AccountControllerConcern
 
   def index
-    @accounts = @account.followers.page(params[:page]).per(FOLLOW_PER_PAGE)
+    @follows = Follow.where(target_account: @account).order(id: :desc).page(params[:page]).per(FOLLOW_PER_PAGE).preload(:account)
   end
 end

app/controllers/following_accounts_controller.rb

@@ -4,6 +4,6 @@ class FollowingAccountsController < ApplicationController
   include AccountControllerConcern
 
   def index
-    @accounts = @account.following.page(params[:page]).per(FOLLOW_PER_PAGE)
+    @follows = Follow.where(account: @account).order(id: :desc).page(params[:page]).per(FOLLOW_PER_PAGE).preload(:target_account)
   end
 end

app/views/accounts/_follow_grid.html.haml

@@ -4,4 +4,4 @@
   - else
     = render partial: 'accounts/grid_card', collection: accounts, as: :account, cached: true
 
-= paginate accounts
+= paginate follows

app/views/follower_accounts/index.html.haml

@@ -6,4 +6,4 @@
 
 = render 'accounts/header', account: @account
 
-= render 'accounts/follow_grid', accounts: @accounts
+= render 'accounts/follow_grid', follows: @follows, accounts: @follows.map(&:account)

app/views/following_accounts/index.html.haml

@@ -6,4 +6,4 @@
 
 = render 'accounts/header', account: @account
 
-= render 'accounts/follow_grid', accounts: @accounts
+= render 'accounts/follow_grid', follows: @follows, accounts: @follows.map(&:target_account)