Foreman Maintain

Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1563211

Description of problem:
Service command in foreman-maintain operates only on local postgresql service. Even when Satellite is configured to use remote Mongo DB the foreman-maintain service restarts local postgres and returns its status.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. configure Satellite with remote DB for Foreman and/or Candlepin
2. foreman-maintain service stop
3. see the local postgresql was stopped

Actual results:
Local postgresql was stopped

Expected results:
Local postgresql keeps running if installed and not used by neither of the satellite databases.
Maybe warning that the DB is remote and can not be stopped

Additional info:

foreman-maintain service status should return some status of the remote Postgres DB (if we can connect with our current setup, if the serice is up, that it is remote and can not be stopped, maybe ping latency and ssl presence on the connection)

foreman-maintain start should check if the remote DB is up and accessible

Another scenarios worth considering:
- only one DB is remote
- Foreman DB is MySQL (or sqlite)