Add ability to generate horizon options

For horizon dashboard:
1) if horizon enabled
2) if nginx-proxy enabled, get from nginx pillar: protocol, ip, port
3) if nginx-proxy disabled, get default protocol 'http', ip get from pillar 
'_param.cluster_local_address', port from horizon pillar bind port

Change-Id: Ia089dd8273314a3830c1f552357a8cdb4f14e0a1
Related-Prod: PROD-17611
3 files changed