Policy list and Pdpgroup merger code

Policy list and Pdpgroup merger code

Draft code of the policy list/pdpgroup merger + tests, this code will most likely be called by a camel Rest route and the answer will be returned to the client/ui. The policies listing is enriched with new fields pdp group info, like:
  1. In which Pdp group/Subgroup the policy is currently deployed
  2. What are the potential pdpgroups/subgroups where the policy can be deployed

  These info will be shown in the policy clamp UI to the user.

Also some refactoring has been done for the sake of clarity.

Issue-ID: POLICY-2924
Signed-off-by: sebdet <sebastien.determe@intl.att.com>
Change-Id: Iba1ab6fea90735551d7d2e2bbff9ab2efdee093e
Signed-off-by: sebdet <sebastien.determe@intl.att.com>
(cherry picked from commit 76a0b386bcf5f30533c85f6d26c559bea19ce0fb)