New: Enable access control

[taylortom]

Context

Part of the generic _access mechanism — see adapt-security/adapt-authoring-api#98.

Summary

Call this.enableAccessControl() in init() to opt into the _access system, enabling sharing of content plugins via _access.public, _access.users, and _access.groups.

Dependencies

• Requires New: Add generic _access mechanism to AbstractApiModule adapt-authoring-api#98