Description of problem:
The deployment files from `openstack overcloud config download` are not portable. Starting with Ansible 2.8 (and especially now with the release of 2.10), there is a huge focus on portable and consumable collections.
Version-Release number of selected component (if applicable):
RHOSP <= 16.1
Steps to Reproduce:
1. `openstack overcloud config download`
2. Move the directory it creates to another server (or into Ansible Tower).
3. Execute the playbooks. They will fail because there are missing roles and modules.
`openstack overcloud config download` only provides the task files that are generated from THT.
All of the required dependencies (including roles and modules) should be copied over to the config-download directory.
$ openstack overcloud config download --collection
$ ls -1 tripleo-ansible
Related spec for Ansible Tower (AWX) integration: https://review.opendev.org/#/c/698828/
Per discussions during the Wallaby PTG, this will no longer be pursued.