internal/boundary: add GetResourceType to Resource

The resource type method is used to automatically
create refresh tokens from a resource when that
resource is the last item returned in a page.

This also renames the iam domain ResourceType method
to GetResourceType to align with the new method.

internal/host/plugin/host_set.go

@@ -14,6 +14,7 @@ import (
 	"github.com/hashicorp/boundary/internal/errors"
 	"github.com/hashicorp/boundary/internal/host/plugin/store"
 	"github.com/hashicorp/boundary/internal/oplog"
+	"github.com/hashicorp/boundary/internal/types/resource"
 	"google.golang.org/protobuf/proto"
 )
 
@@ -65,6 +66,11 @@ func (s *HostSet) SetTableName(n string) {
 	s.tableName = n
 }
 
+// GetResourceType returns the resource type of the HostSet
+func (s *HostSet) GetResourceType() resource.Type {
+	return resource.HostSet
+}
+
 func allocHostSet() *HostSet {
 	return &HostSet{
 		HostSet: &store.HostSet{},