Split up as_set into a set_table and an as_set. The first is what does

Split up as_set into a set_table and an as_set. The first is what does
the lookup and will now also be used in roa-set tries. The as_set is glue
to add the name and dirty flag. Add an accessor to get the set data so
that the imsg sending and printing can be moved into the right places.
This is done mainly because roa-sets need similar but slightly different
versions and making the code more generic is the best way fixing this.
OK benno@