[repoapi] move get_repository function into a new repoapi module
This new module aims to host the function of the new API replacing the old
DBAPI. `get_repository` is still needed hence moved to the new module.
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 precreate script, executed at instance creation time or when
the cube is added to an existing instance, before the schema is serialized.
This is typically to create groups referenced by the cube'schema.
"""