Add CLI command to list projects

[pombredanne]

It would be useful to list projects from CLI. Ideally we could have a simple listing with one per line, and a more verbose listing with extra details

[tdruez]

New scanpipe list-project CLI command available, documented at https://scancodeio.readthedocs.io/en/latest/command-line-interface.html#scanpipe-list-project-search-search-include-archived