PVE::CLIHandler - allow to define additional parameters for output formatter

Best shown with a example:

my $test_formatter = sub {
    my ($res, $result_schema, $fmt_param) = @_;
    PVE::CLIFormatter::print_api_result($res, $result_schema, undef, $fmt_param);
};

$cmddef = [ __PACKAGE__, 'test', [], undef, $test_formatter, $PVE::RESTHandler::standard_output_options],