- Use canonical content address JSON format for floating content
addressed derivation outputs
This keeps it more consistent.
- Reorganize inputs into nested structure (`inputs.srcs` and
`inputs.drvs`)
This will allow for an easier to use, but less compact, alternative
where `srcs` is just a list of derived paths.
It also allows for other experiments for derivations with a different
input structure, as I suspect will be needed for secure build traces.
This continues the work for formalizing our current JSON docs. Note that
in the process, a few bugs were caught:
- `closureSize` was repeated twice, forgot `closureDownloadSize`
- `file*` fields should be `download*`. They are in fact called that in
the line-oriented `.narinfo` file, but were renamed in the JSON
format.
We immediately use this in the JSON schemas for Derivation and Deriving
Path, but we cannot yet use it in Store Object Info because those paths
*do* include the store dir currently.
