Enable redis/sentinel port and sentinel master name configuration

Enable redis/sentinel port and sentinel master name configuration

This change enables configuration of DBAAS_MASTER_NAME,
DBAAS_SERVICE_PORT and DBAAS_SERVICE_SENTINEL_PORT value
configuration for different clusters. Environment variable values
are comma separated lists.

For example if the DBAAS_CLUSTER_ADDR_LIST environment variable has
three cluster addresses then it ispossible to configure each
cluster different values like:

 DBAAS_MASTER_NAME='dbaasmaster-0,dbaasmaster-1,dbaasmaster-2'
 DBAAS_SERVICE_PORT='6379,6380,6381'
 DBAAS_SERVICE_SENTINEL_PORT='26379,26380,26381'

Notice: RIC platform deployments above list type of environment
variables will have a single value (only one Database (DB) service
is supported).

SDL version 1.6.0

Issue-Id: RIC-698

Change-Id: Ib07243da0fd973623dfeb09b82c000d19be11a7d
Signed-off-by: Petri Ovaska <petri.ovaska@nokia.com>