Add endpoint to see hostdb filtermode and update siac hostdb methods
This MR adds the API endpoint to see the current filtermode of the hostdb. Additionally it updates the current siac hostdb filtermode
command to show the filtermode and filtered host. The previous functionality was moved to siac hsotdb setfiltermode
which was also updated to accept host pubkeys as individually arguements instead of a comma separated list.
Edited by Matthew Sevey