[tripleo-common] Enhance List Roles action to provide full contents

Enhance existing ListRolesAction which lists roles currently selected for deployment by reaching to deployment plan for roles_data.yaml object to optionally include entire contents of each role rather than just role names.

input: { container: <planName>, detail: true }
output:
[
  {
    name: 'BlockStorage',
    description: 'Cinder Block Storage node role',
    networks: ['InternalApi', 'Storage', 'StorageMgmt'],
    servicesDefault: [ 'OS::TripleO::Services::AuditD', ... ],
    ...
  },
   ...
]

This action differs from ListAvailableRolesAction by reaching to roles_data.yaml rather than to 'roles directory' in Swift container.
'roles directory' - roles available for use in deployment
'roles_data.yaml' - roles which are selected to be used for deployment. Any changes to roles configuration is stored here (e.g. networks assignment). That is why we need to duplicate the data.