Avoid using Puppet host parameters

[stdevel]

Is your feature request related to a problem? Please describe.
There is no problem, but it would be a good idea to avoid using Puppet host parameters as there are currently plans to integrate Spacewalk (#43) ans Spacewalk does not offer Puppet host parameters.

Describe the solution you'd like
katprep-related configuration should be stored in a different location.

Describe alternatives you've considered
An option would be leveraging a SQLite database.

Additional context

[stdevel]

As Red Hat Satellite 7.x will not come with Puppet, we need to find a solution sooner.

[stdevel]

Using Redis would be a solution that might also have a positive impact on performance.

[stdevel]

It needs to be clarified whether the parameters functionality in Foreman will be dropped when removing Puppet support.