NodeLoader: Store standard checksums as ExtIDs in addition to NAR ones
requested to merge anlambert/swh-loader-core:node-loader-store-standard-checksum-as-exit into master
The NodeLoader class handles two checksums layout:
- standard: checksum is computed from the raw downloaded artifact bytes
- nar: checksum is a NAR hash, recursively computed from source code tree
Previously, only nar checksums were stored as ExtIDs while standard ones were only used for integrity checks after downloads.
As mapping a tarball (resp. file) standard checksum to its corresponding directory (resp. content) SWHID is of interest for Guix to check if SWH archived this software artifact, ensure to also save standard checksums as ExtIDs of type "checksum-<hash_algo>".