Method to pretty-print duration from seconds or milliseconds

[hyperair]

Is your feature request related to a problem? Please describe.
I have many log lines with labels like duration=1000 for 1 second, and duration=3600000 for 1 hour. I'd like to have this pretty printed into either a hh:mm:ss kind of format, or even something like 1h 30m 1.123s

Currently the closest I've gotten is to use | label_format duration_pretty={{ if .duration }}{{ .duration | printf "%sms" | duration | printf "%.3f" }}s{{ end }}`

Describe the solution you'd like
I would like a template function that's exactly the reverse of duration_seconds, i.e. I would like it to take a number (of seconds), and convert it into a humanized time duration.

Describe alternatives you've considered
This is the current workaround I've arrived at:

  | label_format duration_h=`{{ if .duration }}{{ div .duration 3600000 }}{{ end }}`, duration_m=`{{ if .duration }}{{ div .duration 60000 }}{{ end }}`, duration_s=`{{ if .duration }}{{ div .duration 1000 }}{{ end }}`
  | label_format duration_pretty=`{{ if .duration }}{{ if .duration_h | int }}{{ .duration_h | int | printf "%d" }}h {{ end }}{{ if mod .duration_m 60 }}{{ mod .duration_m 60 | printf "%d"}}m {{ end }}{{ mod .duration_s 60 | printf "%d"}}.{{ mod .duration 1000 | printf "%03d"}}s{{ end }}`

Additional context
N/A