Visualize queried point clouds using Open3D

[jarkenau]

This PR add as prompt for visualizing the queried point clouds (via FlatBuffers) using Open3D.

...
---Is dense--- 
 True
---Payload--- 
 [(0., 0., 0.,  3.,        0, 0,  0, 6338, 0)
 (0., 0., 0., 10.,    96512, 0,  0, 6283, 0)
 (0., 0., 0., 17.,   197120, 0,  0, 6189, 0) ...
 (0., 0., 0.,  8., 99670528, 0, 63, 8333, 0)
 (0., 0., 0., 14., 99764736, 0, 63, 8160, 0)
 (0., 0., 0.,  1., 99857408, 0, 63, 8119, 0)]
------------
Visualize the point cloud? (Y/N) 

Example visualization: