Add appeals (#17364)

* Add appeals

* Add ability to reject appeals and ability to browse pending appeals in admin UI

* Add strikes to account page in settings

* Various fixes and improvements

- Add separate notification setting for appeals, separate from reports
- Fix style of links in report/strike header
- Change approving an appeal to not restore statuses (due to federation complexities)
- Change style of successfully appealed strikes on account settings page
- Change account settings page to only show unappealed or recently appealed strikes

* Change appealed_at to overruled_at

* Fix missing method error

app/services/approve_appeal_service.rb

@@ -0,0 +1,74 @@
+# frozen_string_literal: true
+
+class ApproveAppealService < BaseService
+  def call(appeal, current_account)
+    @appeal          = appeal
+    @strike          = appeal.strike
+    @current_account = current_account
+
+    ApplicationRecord.transaction do
+      undo_strike_action!
+      mark_strike_as_appealed!
+    end
+
+    queue_workers!
+    notify_target_account!
+  end
+
+  private
+
+  def target_account
+    @strike.target_account
+  end
+
+  def undo_strike_action!
+    case @strike.action
+    when 'disable'
+      undo_disable!
+    when 'delete_statuses'
+      undo_delete_statuses!
+    when 'sensitive'
+      undo_sensitive!
+    when 'silence'
+      undo_silence!
+    when 'suspend'
+      undo_suspend!
+    end
+  end
+
+  def mark_strike_as_appealed!
+    @appeal.approve!(@current_account)
+    @strike.touch(:overruled_at)
+  end
+
+  def undo_disable!
+    target_account.user.enable!
+  end
+
+  def undo_delete_statuses!
+    # Cannot be undone
+  end
+
+  def undo_sensitive!
+    target_account.unsensitize!
+  end
+
+  def undo_silence!
+    target_account.unsilence!
+  end
+
+  def undo_suspend!
+    target_account.unsuspend!
+  end
+
+  def queue_workers!
+    case @strike.action
+    when 'suspend'
+      Admin::UnsuspensionWorker.perform_async(target_account.id)
+    end
+  end
+
+  def notify_target_account!
+    UserMailer.appeal_approved(target_account.user, @appeal).deliver_later
+  end
+end