Add role specific information to the service template

Add role specific information to the service template

When a service is enabled on multiple roles, the parameters for the
service will be global. This change enables an option to provide
role specific parameter to services and other templates.

Two new parameters - RoleName and RoleParameters, are added to the
service template. RoleName provides the role name of on which the
current instance of the service is being applied on. RoleParameters
provides the list of parameters which are configured specific to the
role in the environment file, like below:

  parameters_default:
      # Default value for applied to all roles
      NovaReservedHostMemory: 2048
      ComputeDpdkParameters:
          # Applied only to ComputeDpdk role
          NovaReservedHostMemory: 4096

In above sample, the cluster contains 2 roles - Compute, ComputeDpdk.
The values of ComputeDpdkParameters will be passed on to the templates
as RoleParameters while creating the stack for ComputeDpdk role. The
parameter which supports role specific configuration, should find the
parameter first in in the RoleParameters list, if not found, then the
default (for all roles) should be used.
Implements: blueprint tripleo-derive-parameters

Change-Id: I72376a803ec6b2ed93903cc0c95a6ffce718b6dc