[EAGLE-1044] Support policy Import using a policy prototype

https://issues.apache.org/jira/browse/EAGLE-1044'

Provided APIs:
*  load policies to new site "sandbox" from policy prototypes by `POST /rest/policyProto/loadToSite/sandbox`
* create a new policy prototype with an existing policy by `POST /rest/policyProto/saveAsProto`
* update or create a policy prototype by by `POST /rest/policyProto`
* get all policy prototypes by `GET /rest/policyProto`
* delete a policy prototype by `DELETE /rest/policyProto/{uuid}`

Author: Zhao, Qingwen <qingwzhao@apache.org>

Closes #952 from qingwen220/EAGLE-1044.
15 files changed