Closes: #1135
Closes: #1026
Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

It is now possible to deactivate selected authentication methods
(basic auth, token auth) inside the cluster by adding
removing the required arguments to the Kube API Server and generating
the secrets accordingly.

The x509 authentification is currently not optional because disabling it
would affect the kubectl clients deployed on the master nodes.

To use OpenID Connect Authentication beside deploying an OpenID Connect
Identity Provider it is necesarry to pass additional arguments to the Kube API Server.
These required arguments were added to the kube apiserver manifest.

Operator can specify any port for kube-api (6443 default) This helps in
case where some pods such as Ingress require 443 exclusively.

Closes: 820
Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

Closes: #1073
Signed-off-by: Sergii Golovatiuk <sgolovatiuk@mirantis.com>

* Leave all.yml to keep only optional vars
* Store groups' specific vars by existing group names
* Fix optional vars casted as mandatory (add default())
* Fix missing defaults for an optional IP var
* Relink group_vars for terraform to reflect changes

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>