Adds support for HTTP basic authentication with the Docker registry.

The kolla docker registry password is now written to passwords.yml.

Change-Id: Ie6e854a66a6660d4e02771fe2b5dd97af814194d
Story: 2007952
Task: 40429

This allows us to add configuration scenarios.

Change-Id: Id636f78c61237fb27fa65fa3d4b3fc1a4cf0ba6a
Story: 2004360
Task: 40777

Adds support for enabling TLS on the Docker registry.

Change-Id: Idac6a1dfb17f4a22b3043531d1181a5585cafe6a
Story: 2007952
Task: 40428