Create a workflow to properly expose the 'tripleo.parameters.get_flatten' action

[Ryan Brady]

The 'tripleo.parameters.get_flatten' action is called directly as an action and should instead be called via a workflow. Create a workflow to expose this action and if the logic can be replicated in the workflow, deprecate the action.

PARAMETERS_GET - https://github.com/openstack/tripleo-ui/blob/master/src/js/constants/MistralConstants.js#L29

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/558883

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/558883
Committed: https://git.openstack.org/cgit/openstack/tripleo-common/commit/?id=84b76ef66c931d7f09959e88cbd296ef86e1bd5b
Submitter: Zuul
Branch: master

commit 84b76ef66c931d7f09959e88cbd296ef86e1bd5b
Author: Mike Fedosin <email address hidden>
Date: Wed Apr 4 19:14:07 2018 +0200

    Create get_flattened_parameters workflow

    The 'tripleo.parameters.get_flatten' action is called directly
    as an action in tripleo-ui and should instead be called via a
    workflow.

    This code create the related workflow that will be used instead
    of the action

    Change-Id: I2b560dc084f54042598b72c9c3280ccfa2a4181a
    Fixes-bug: #1759413