[server] Refactor Repository.register_user into a CubicWeb service (closes #3020639)
[jcr: move commit to the caller; add item in release notes; fix NameErrors]
usr/lib/PY_VERSION/*-packages/cubicweb/devtools/
usr/lib/PY_VERSION/*-packages/cubicweb/skeleton/
usr/lib/PY_VERSION/*-packages/cubicweb/test
usr/lib/PY_VERSION/*-packages/cubicweb/entities/test
usr/lib/PY_VERSION/*-packages/cubicweb/ext/test
usr/lib/PY_VERSION/*-packages/cubicweb/server/test
usr/lib/PY_VERSION/*-packages/cubicweb/sobjects/test
usr/lib/PY_VERSION/*-packages/cubicweb/hooks/test
usr/lib/PY_VERSION/*-packages/cubicweb/web/test
usr/lib/PY_VERSION/*-packages/cubicweb/etwist/test