Disable resolved messages at the alert rule level instead of contact point

### Discussed in https://github.com/grafana/grafana/discussions/65564 <div type='discussions-op-text'> ^{Originally posted by **vikram0602** March 29, 2023} Is there a way to configure alert to enable or disable triggering resolved messages. So for example we want to send resolve messages for some alerts but not for all alerts. I see you can enable triggering resolved messages on contact points but would be great to set that on alert itself.</div>