New features

Update to work with Core Drupal 8.5.x layout builder

• Reformat codes
• Move files into root and not subfolder
• Possibility to add a description to field
• Small bugfixing: empty option in select input, hidden fields, missing header title in formazing dashboard

- Change Expire durations settings
- Add Delete All options

Added the possibility to override the default behaviour that acting users do not receive notifications for their own generated events.
To allow these notifications, use the newly introduced parameter $notifyActingUser (default False) in hook_flag_notify_event_alter()