ENH: Supernova volumetric redshift rate

[itrharrison]

Description

This is a re-do of #140 to change the target branch to module/supernovae

Checklist

• [ ] Follow the Contributor Guidelines
• [ ] Write unit tests
• [ ] Write documentation strings
• [ ] Assign someone from your working team to review this pull request
• [ ] Assign someone from the infrastructure team to review this pull request