Default extension of point clouds to be `.copc.laz` instead of `.laz` ?

[CharlesGaydon]

For larger patches this would make visualization more efficient, and facilitate random patch cropping at training time (i.e. data augmentation).
It's only a small change in code, and .copc.laz is in essence a .laz so we would not lose any functionnality.

https://pdal.io/en/2.6.0/stages/writers.copc.html