This patch updates the endpoints used for the project management
subcommands to avoid the soon-to-be deprecated overview endpoint.

The `phylum project update` subcommand has been updated to make use of
the new `default_label` field, which can now be updated.

The `phylum project list` subcommand now lists all projects by default,
including group projects. To still allow listing only non-group projects
the new `--no-group` flag has been added to this subcommand
specifically. The `repository_url` has been removed from the command
output, since it is not included in the API response.

The group name has been removed from `phylum project status`, since the
new endpoint used by the subcommand does not return this information.
However the `default_label` field was added instead.

Closes #1439.