Add Events for async_call_remote_service

[zanix]

Home Assistant 2023.6 changed persistent notifications to no longer be entities. Before 2023.6, I had automations that were triggered by the creation of these notifications to create additional notifications and other actions from the events from this integration.

I created this PR to add events so these automations can be retained.

• subaru_command_sent - data: {command, car_name}
• subaru_command_successful - data: {command, car_name}
• subaru_command_failed - data: {command, car_name, message}