Both include_role and import_role expect role's name to be given
via "name" param instead of "role".
This worked but caused errors with ansible-lint.
See: https://review.opendev.org/694779

Change-Id: I388d4ae27111e430d38df1abcb6c6127d90a06e0

This patch adds initial support for deploying multiple Nova cells.

Splitting a nova-cell role out from the Nova role allows a more granular
approach to deploying and configuring Nova services.

A new enable_cells flag has been added that enables the support of
multiple cells via the introduction of a super conductor in addition to
cell-specific conductors. When this flag is not set (the default), nova
is configured in the same manner as before - with a single conductor.

The nova role now deploys the global services:

* nova-api
* nova-scheduler
* nova-super-conductor (if enable_cells is true)

The nova-cell role handles services specific to a cell:

* nova-compute
* nova-compute-ironic
* nova-conductor
* nova-libvirt
* nova-novncproxy
* nova-serialproxy
* nova-spicehtml5proxy
* nova-ssh

This patch does not support using a single cell controller for managing
more than one cell. Support for sharing a cell controller will be added
in a future patch.

This patch should be backwards compatible and is tested by existing CI
jobs. A new CI job has been added that tests a multi-cell environment.

ceph-mon has been removed from the play hosts list as it is not
necessary - delegate_to does not require the host to be in the play.

Documentation will be added in a separate patch.

Partially Implements: blueprint support-nova-cells
Co-Authored-By: Mark Goddard <mark@stackhpc.com>
Change-Id: I810aad7d49db3f5a7fd9a2f0f746fd912fe03917

The idea is to factor out a role for deploying Nova related services
to cells. Since all deployments use cells, this role can be used
in both regular deployments which have just cell0 and cell1,
and deployments with many cells.

Partially Implements: blueprint support-nova-cells
Change-Id: Ib1f36ec0a773c384f2c1eac1843782a3e766045a

With this change, an operator may be able to stop a
service container without stopping all services in a host.
This change is the starting point to start
fast-forward upgrades support.
In next changes new flags will be introducced to disable
stop dataplane services during upgrades.

Change-Id: Ifde7a39d7d8596ef0d7405ecf1ac1d49a459d9ef
Implements: blueprint support-stop-containers