NRRD poc - 2nd loader to be tested

[ddelpiano]

ThreeJD loder - Evaluated and does not meet all the requirements.

LeBarba webgl - To be tested
Three 2nd example - To Be tested (I would live this as last since this might be affected by the memory issue as well).

Re-work the poc to use one of the other 2 alternative as loaders focusing also on the issue already encountered on the previous laoder (memory issue, load multiple nrrd instances in the same scene).