Allow setting inboundPorts for SameServerEntity

The `SameServerEntity` now uses the union of the `inboundPorts` provisioning flag and the `getRequiredOpenPorts()` collection to specify the complete set of ports to open. This allows the `inboundPorts` flag to be set of the entity itself, which is useful when one of the children is only instantiated from an `EntitySpec` at `start(...)` time, so will not have its ports picked up.