Add checkbox to show only open tickets on dashboard widgets

The Tickets by Assignee and group seem better served to be done for only open tickets, I think adding a checkbox or adding another category that gives folks the option.

I added "$t_table.status" => \Ticket::getNotSolvedStatusArray(), to line 821 on provider.class.php and achieved the results I wanted.

If I get time I'll assist coding this in, but not likely going to happen