Validator: Various run fails

[Cristian Le]

Continuing to understand and debug a simple stack from the deployment guide without the CIs that do not match the documentation, I've been encountering several issues with the validator. The stack itself is not in a functional state, but the validator does not indicate what is wrong with it. The problem with the problems with the validator are:

1. The inventory needed to properly run it are based on the inventories in e.g. `tripleo-deploy/undercloud/tripleo-ansible-inventory.yaml`. However these files are only generated after running `undercloud install` or `overcloud deploy`, which defeats the purpose of `pre-deploy` and `prep`.

2. Many of the errors are due to probable deprecations.
E.g. in `undercloud-tokenflush` in `pre-introspection` there's the error
```
Failed to retrieve hiera data for keystone::token_provider
```
but there is no keystone installed on undercloud by the default configurations, as enabling that gives other issues.

3. Some validators are wrong.
E.g. in `validate-selinux` in `pre-deployment` there's the error
```
Source /tmp/denials.log not readable
```
which only occurs if the file is non-zero in size and as it is created with `600 root:root`.

4. The issue/missconfiguration that are wrong with the current deployment are not reflected. The current issue seems to be a communication issue with the services.
E.g. running `openstack volume create --size 10 'Test Volume'`, I get
```
Gateway Timeout (HTTP 504)
```
and similarly for other commands, such as when making a compute node, it is stuck in queue.

I have attached the artifacts of this deployment and validator runs