cubicweb #17207462 update skeleton debian packaging (py2 and py3) [done]

In cubicweb/skeleton lives the packaging debian template for new cubes (created by "cubicweb-ctl new-cube" command). Currently, this packaging produces binary packages for python2 named cubicweb-<cubename>. We should instead produce python-cubicweb-<cubename> and python3-cubicweb-<cubename> binary packages.

prioritynormal
typetask
done in3.26.x
load left0.000
closed by<not specified>