Policy Management API Draft implementation with two basic methods: getPolicy, setPolicy

Jira issue: WP-932
Policy Management API: Added implementation made by glatorre in webinos/core/wrt/lib/webinos.policymanagement.js

Jira-issue: WP-932
Added reference to default policies' folder

Jira issue: WP-932
Policy Management API files moved to create the modularised version

Jira issue: WP-932