feat(tvix/glue/fetchers): add NAR fetching infrastructure r/8252

The magic <nix/fetchurl.nix> derivation can cause two other types of
fetch to happen, one that unpacks NAR files, and another one that puts a
file as an executable at the store path root.

This adds the necessary enum type and path calculation logic for it to
the fetcher code.

It also adds code to do the actual NAR fetching. The executable case is
still stubbed out.

Change-Id: I79103fd58c7e22ad7fde34efa5e2d89cad7d5a0e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11790
Reviewed-by: Connor Brewster <cbrewster@hey.com>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI

0 files changed, 0 insertions, 0 deletions