vault: Fix vault response schema

Names got changed and, unfortunately, it was not caught neither by vault tests nor swh-web's ¯_(ツ)_/¯.

wip and incomplete (needs to fix tests now)

In docker, i no longer reproduce with this.

Test Plan

tox

docker

$ cd swh-web && yarn build-dev
$ emacs docker-compose.override.yml  # and add the swh-web override mount points with the local swh-web repository
$ docker-compose up
$ # load some repository
$ # request some cooking
$ # check the listing now works

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Migrated from D4521 (view on Phabricator)