Move console scripts to entrypoints.

As part of the move of plugins to entrypoints, take advantage of the
entrypoints based console scripts, which will make our command line scripts
available for unittesting.

Part of blueprint entrypoints-plugins

Co-authored-by: Michael Still <mikal@stillhq.com>

Change-Id: I5f17348b7b3cc896c92263dd518abb128757d81f
Merge "Move console scripts to entrypoints."