Decouple EndpointMap from SSL certificate params

Decouple EndpointMap from SSL certificate params

Having the endpoint map in the same environment as the SSL
certificate parameters means that every time a service is added to
the overcloud, the user must remember to update their copy of
enable-tls.yaml to reflect the new service.

To avoid this, let's separate the SSL EndpointMap from the SSL
certificates so users can simply pass the shipped list of SSL
endpoints and only have to customize the certificate env file. As
and added bonus, this means they won't have to put the certificates
in enable-tls.yaml specifically.  The parameters can be set
anywhere, and will be used as long as one of the tls-endpoints
envs is also specified.

inject-trust-anchor.yaml is not changed, but it could already be
used in the same fashion.  The root certificate param could be set
in any env passed after inject-trust-anchor.yaml, and then
inject-trust-anchor.yaml would only be responsible for setting the
appropriate resource_registry entry.  This way there is no need to
customize the in-tree inject-trust-anchor.yaml either.

Change-Id: I38eabb903b8382e6577ccc97e21fbb9d09c382b3