step_ca_provisioner: Make idempotent (remove 'updated' state)

[maxhoesel]

Right now, the step_ca_provisioner module has two possible states present and updated.
Present only creates provisioners while updated only updates existing ones.
This is a pretty thin wrap over the underlying CLI commands and doesn't really do what a user most likely wants: Ensure that a provisioner with the required parameters is present under all reasonable circumstances.

I suggest adding a simple comparsion logic to the step_ca_provisioner command, i.e. by comparing the provisioner config against provided values to check whether a provisioner needs to be updated.