Enable service control for puppetdb

Hello,

I added some bits to the module to allow disabling the puppetdb service, but still have puppetdb deployed and configured . Our use case would be something like this: we have a backup puppetdb machine with postgres in recovery and a puppetdb pointed to that database. We wanted to disable the service so it doesn't try to actually use the database. When we want to switch to the backup machine we just take the database out of recovery mode and enable the puppetdb service.