Add flag for an org to say if it manages its own redirects

We default to false and will produce some way of detecting and setting this in a further commit.
Add importer to toggle flag on orgs for managing their own redirects

Looks at all their hosts, if they all are gds_managed? we set the manages_own_redirects? flag to false, otherwise we set it to true.
Add some more import tasks to load.sh

1. dns lookup for hosts
2. setting the manages_own_redirects flag for orgs