Allow the editing of file provisioned alerts in the UI

This is an extension of https://github.com/grafana/grafana/issues/57911#issuecomment-2022963330. We want to provision our alerts consistently across environments, however we want to allow the editing of the rules in the UI (because then the process is to export the config and commit it to git). It would be really good if alert groups in the provisioning yaml had an `editable: true|false` flag, similar to that of dashboards etc. The current work around is to run a post-deploy script to execute some SQL (`UPDATE provenance_type SET provenance = '' WHERE record_type = 'alertRule'`)