draco: Pointclouds with NaNs are damaged by compression (Melodic) or fail (Noetic)

[peci1]

According to google/draco#633 (comment), draco cannot compress invalid float values. Howerver, draco_point_cloud_transport doesn't filter non-dense clouds to remove the invalid points before passing the cloud to draco.

On melodic with its older draco version, this does result in silent damage done to the pointcloud

On noetic, this results in the following error:

Error encoding message by transport draco: Draco encoder returned code -1: Failed to encode point attributes...

[peci1]

Fixed in 4642f9a .