[repository] add an ``internal_cnx`` method to replace ``internal_session``
Accessing the repo through a Session is deprecated. We need an easy replacement
for ``internal_session``.
This API change was a good occasion to stop disabling integrity hook by default.
This is huge source of bug in user-code.
related to #2503918
# -*- coding: utf-8 -*-
# copyright %(year)s %(author)s, all rights reserved.
# contact %(author-web-site)s -- mailto:%(author-email)s
#
%(long-license)s
"""%(distname)s entity's classes"""