Restful refactor of accounts/ routes (#2133)

* Add routing specs for accounts followers and following actions

* Use more restful route naming for public account follow pages

Moves two actions:
- accounts#followers to accounts/follower_accounts#index
- accounts#following to accounts/following_accounts#index

Adds routing spec to ensure prior URLs are preserved.

app/controllers/following_accounts_controller.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class FollowingAccountsController < ApplicationController
+  include AccountControllerConcern
+
+  def index
+    @accounts = ordered_accounts.page(params[:page]).per(FOLLOW_PER_PAGE)
+  end
+
+  private
+
+  def ordered_accounts
+    @account.following.order('follows.created_at desc')
+  end
+end