Show less information when we run with a single verbosity (``-v``):

- no longer shows accepted interpreters information (as the last proposed one is always the accepted one),
- do not display the ``str_spec`` attribute for ``PythonSpec`` as these can be deduced from the other attributes,
- for the ``app-data`` seeder do not show the type of lock, only the path to the app data directory,

By :user:`gaborbernat`.
