move metadata registration into a separate process

[MattWellie]

Motivation

Addition of the mandatory metamist file registration was dumb, and will break the MSFT implementation.

Given that I'm planning to ditch work on this codebase for a while I'm rolling a few currently open issues into this single change.

Fixes

• Closes #277 (?)
• Closes #271
• Closes #270
• Closes #45

Proposed Changes

• Don't make metadata registration a mandatory part of the HTML generation
• Break Result JSON, HTML, and Metadata registration into 3 separate processes
• Allow for the possibility of alternative scripts for HTML/other output generation - allow each alternative script to have different inputs
  • send all the keyword arguments you want to the output generation job, the chosen script will choose the arguments relevant to it based on the mini config
• Allow for the potential of multiple metadata registration tools, registering most/all of the new files created with this run
  • similar process, though all that's being provided is the list of files and the relevant pedigree, the service-relevant content will be defined in the script

Checklist

• [x] Related Issue created
• [ ] Tests covering new change
• [x] Linting checks pass

[MattWellie]

https://test-web.populationgenomics.org.au/ohmr3-mendelian/reanalysis/chr2_denovo_test/summary_output.html was generated using this form (limited to just chr2 variants in the latest ohmr3-mendelian joint call)

Note - there are two samples reaching the report, from the same family, so there's a bunch of similar identifiers but I've checked that it's accurate

[jeremiahwander]

Thanks for the refactor, this is going to be really helpful on our end!