Upgrade/Downgrade breadcrumbs

Following discussion from: #1387

When running the up/downgrade functions, it _might_ be desirable to leave breadcrumbs of some kind.

Proposal from @meshula:
```json
{
"from": 3,
"to": 2,
"action": "downgrade",
"on": "DD-MM-YYYY HH:MM"
}
```

Potential issues:
- performance
- data validity/lifetime (if data gets passed around, is it still accurate?)
- relevancy

No files, tests, or entry points are named. Read the discussion in #1387 and this proposal first, then assess the listed performance, data validity/lifetime, and relevancy concerns. Done means the breadcrumb behavior and its scope are clearly agreed.

Written by the indexing model from the issue text.