maven: Use most recent release of a package as default version

artifacts list sent by the lister is not guaranteed to be sorted
by artifact time so the last element is not necessarily the most
recent artifact.

So ensure to use the most recent artifact as default version by
sorting the artifacts by their ISO 8601 date representation
(designed for lexicographical sort). If a date failed to be
parsed by the lister (edge case but can happen), the time value
will be an empty string so the sort operation will not end up
with error.

Related to T3874