We add a new set of builtins called `import_builtins`, which
will contain import-related builtins, such as `builtins.path` and
`builtins.filterSource`. Both can import paths into the store, with
various knobs to alter the result, e.g. filtering, renaming, expected
hashes.
We introduce `filtered_ingest` which will drive the filtered ingestion
via the Nix function via the generator machinery, and then we register
the root node to the path info service inside the store.
`builtins.filterSource` is very simple, `builtins.path` is a more
complicated model requiring the same logic albeit more sophisticated
with name customization, file ingestion method and expected SHA-256.
Change-Id: I1083f37808b35f7b37818c8ffb9543d9682b2de2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10654
Autosubmit: raitobezarius <tvl@lahfa.xyz>
Tested-by: BuildkiteCI
Reviewed-by: flokli <flokli@flokli.de>