Implement Dead Man Monitoring

[nanos]

Give an option to ping a url when script is complete, which can then integrate for example with https://healthchecks.io.

This can be configured with these options:

Environment Variable Name (if using GitHub Action)	Command line flag (if using cron, or the container)	Required?	Notes
ON_START	--on-start	No	Optionally provide a callback URL that will be pinged when processing is starting. A query parameter rid={uuid} will automatically be appended to uniquely identify each execution.
ON_DONE	--on-done	No	Optionally provide a callback URL that will be called when processing is finished. A query parameter rid={uuid} will automatically be appended to uniquely identify each execution.
ON_FAIL	--on-fail	No	Optionally provide a callback URL that will be called when processing has failed. A query parameter rid={uuid} will automatically be appended to uniquely identify each execution.