optional streaming construct?

### Version

4.7.0-SNAPSHOT

### Feature

As far as I can tell, neither tdbquery nor fuseki allow to stream the CONSTRUCT results, eben though the API exists. Of course there are concerns about duplicate triples etc but it might be a nice and heap space conserving optional function

### Are you interested in contributing a solution yourself?

_No response_

Start by examining how tdbquery and Fuseki currently execute and return CONSTRUCT results, then trace the existing streaming API mentioned in the issue. Determine the expected behavior around duplicate triples and make streaming an optional, heap-space-conscious result mode with coverage for the affected entry points.

Written by the indexing model from the issue text.