Optimize repeated db calls

[stefanistrate]

Here are some examples:

• embedding_display.py:

    for result in results:
      window_id = int(result.window_id)
      window = db.get_window(window_id)
      recording = db.get_recording(window.recording_id)
      deployment = db.get_deployment(recording.deployment_id)
      annotations = db.get_all_annotations(
          filter=config_dict.create(
              eq=dict(recording_id=window.recording_id),
              approx=dict(offsets=window.offsets),
          )
      )