'rest' capability for WebSocket Token API

Provides an interface to perform CRUD operations on entities of static and dynamic classes.

To work, the integration_point (webservice) entity, through whose token the connection is made, must have a role with access to the /ws#rest route with the method WEBSOCKET. And also requires binding to a user who has role permission for the requested operation to the endpoint collection in the REST-API.

Each non-empty change is finalized by generating notifications to subscribers.