Move params to hiera

[neomilium]

In order to ease maintenance, this PR modernizes the way to handle params from dedicated class to hiera.

Please note the only behavior change is related to config_file_before pickup:

• before this PR, an OS without specified parameter pick paths-debian.conf on Debian, paths-fedora.conf on RedHat and path-fedora.conf on others.
• now, when its different from Debian or RedHat, the user should provide this parameter.

From my point of view, we should not choose path-fedora.conf when OS is not supported… But I think that choice was motivated. If someone know why, we can now easily add specific configuration using hiera.

Please note the current hierarchy of data selection with hiera is (see hiera.yaml):

hierarchy:
  - name: 'Operating System Family'
    path: '%{facts.os.family}.yaml'

  - name: 'common'
    path: 'common.yaml'

This PR is a starting point to better handle OSes and is related to #132 and some comments in #122.

[neomilium]

@gcoxmoz @alexjfisher Your opinion and review are more than welcome on this PR.

[neomilium]

Superseeded by #135