This patch rehomes neutron.db._model_query into neutron-lib. While
our longer term goal is to use OVO rather than queries and tables, this
module is provided as a stepping stone (as mentioned in release note
herein). The patch also includes a few other APIs that are required for
the rehome including some utils and an exception class.
For more details see the spec on [1].
Also a sample consumption patch can be found on [2]. While it won't work
as-is with the depends on approach (it needs to be rebased on multiple
other DNMs in neutron) I tested it locally. In addition this change
was tested locally with a sample vmware-nsx consumption patch [3].
[1] https://review.openstack.org/#/c/473531/
[2] https://review.openstack.org/#/c/557786/
[3] https://review.openstack.org/#/c/557788/
Change-Id: I3e4b38aa3b6460ce916091c020adedd4ed2c4d26