Add ability to view individual newsletters in admin UI (#39271)

app/controllers/admin/email_subscriptions_controller.rb

@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class Admin::EmailSubscriptionsController < Admin::BaseController
+  before_action :set_email_subscription, only: :destroy
+
   def index
     authorize :email_subscription, :index?
 
@@ -9,6 +11,12 @@ class Admin::EmailSubscriptionsController < Admin::BaseController
     @accounts = Account.local.where.associated(:email_subscriptions).includes(:user)
   end
 
+  def destroy
+    authorize :email_subscription, :destroy?
+    @email_subscription.destroy!
+    redirect_to admin_email_subscriptions_account_path(@email_subscription.account_id)
+  end
+
   def disable
     authorize :email_subscription, :disable?
     Setting.email_subscriptions = false
@@ -20,4 +28,10 @@ class Admin::EmailSubscriptionsController < Admin::BaseController
     Admin::EmailSubscriptionsPurgeWorker.perform_async
     redirect_to admin_email_subscriptions_path, notice: I18n.t('admin.email_subscriptions.purged_msg')
   end
+
+  private
+
+  def set_email_subscription
+    @email_subscription = EmailSubscription.find(params[:id])
+  end
 end