Added a new RM toil dashboard w/ auto deploy job retries table

For issue gitlab-com/gl-infra/delivery#2465 (closed) to create tables in Grafana using the delivery_webhooks_auto_deploy_job_retries metric.

$timeframe is a variable set via a dropdown (1d, 1w, 4w) set by template. Let me know if other timeframe options would be helpful. Feel free to suggest a different name than "timeframe" if there's a better suited terminology for how we use this variable.

$ ./test-dashboard.sh delivery/release_management_toil.jsonnet

(24hrs expiration) https://dashboards.gitlab.net/dashboard/snapshot/MPtZBZjFmrqABq6ZBR8VxM7iTnblN3sR?orgId=1