support local config and policy files

* DCAEGEN2-2733/DCAEGEN2-2753 - onap-dcae-cbs-docker-client support local config and policy files
	Support $CBS_CLIENT_CONFIG_PATH and $CBS_CLIENT_POLICY_PATH,
	Default paths are /app-config/application_config.yaml and /etc/policies/policies.json.
	If files are missing or malformed, drop back to the current behavior.

Change-Id: Iba2484f6be7fc54e412f7de302bb79a4d7bfde17
Signed-off-by: Hansen, Tony (th1395) <th1395@att.com>
Issue-ID: DCAEGEN2-2733
Issue-ID: DCAEGEN2-2753
Signed-off-by: Hansen, Tony (th1395) <th1395@att.com>
9 files changed