Add info command to retrieve information about an ADE object

For now, it only supports retrieving information about an
installed sysroot, but it could be extended to retrieve
information about devices, projects, bundles, etc.

Signed-off-by: Louis-Francis Ratté-Boulianne <lfrb@collabora.com>
Reviewed-by: Guillaume Desmottes <guillaume.desmottes@collabora.co.uk>
Differential Revision: https://phabricator.apertis.org/D5226