babeltrace(1): add the query-info command

babeltrace(1): add the query-info command

The new query-info command is the interface for the query info component
class API:

    babeltrace query-info --sink plugin.sink get-something
    					  --params meow=mix,zoom=18,consider-this=yes

The action is mandatory, as well as exactly one --source/--filter/--sink
option with the plugin and component class names to query info from. If
--params is not omitted, the query info method receives bt_value_null.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>