I marked this PR as a BC break, as it breaks the xml schema generated by the command app/console list --xml

It replaces the first node (currently symfony) by a more generic node name ( application ) and adds the application name and application version if specified in the Symfony\Component\Console\Application constructor.

Before (using composer console that uses symfony console component):

<?xml version="1.0" encoding="UTF-8"?>
<symfony>
    ...
</symfony>

After (using composer console that uses symfony console component):

<?xml version="1.0" encoding="UTF-8"?>
<application name="Composer" version="x.x.x">
    ...
</application>