Update Neutron Grafana dashboard
Update Neutron Grafana dashboard

This patch reflects recent changes in neutron CI jobs configuration
by adding to the dashboard new jobs:
* neutron-von-tempest-ovs-release
* neutron-von-tempest-ovs-release-ipv6-only (non-voting)
* openstack-tox-py38 (non-voting)o

removing from the dashboard jobs:
* test-release-openstack
* networking-midonet-tempest-aio-ml2-centos-7 (non-voting)
* neutron-centos-7-tripleo-standalone (non-voting)

This patch also renames "Scenario jobs failure rates" to be
"Neutron tempest plugin failure rates" graph and moves
neutron-tempest-plugin-api job from the
"Integrated tempest failure rates" graph to this new one.

Change-Id: Id5c5ea4f0bcb0419e3fd13172220fff385c8ee16

openstack-infra/project-config,openstack-infra/project-config