enhancement(graph): refrain from registering routes via the Router interface

After some back an forth we agreed on keeping the routes defined
in a central place for now.

services/graph/pkg/service/v0/graph.go

@@ -59,18 +59,6 @@ type RoleService interface {
 	RemoveRoleFromUser(ctx context.Context, in *settingssvc.RemoveRoleFromUserRequest, opts ...client.CallOption) (*emptypb.Empty, error)
 }
 
-// A Route defines the parameters for an api endpoint
-type Route struct {
-	Method      string
-	Pattern     string
-	HandlerFunc http.HandlerFunc
-}
-
-// Router defines the required methods for retrieving api routes
-type Router interface {
-	Routes() []Route
-}
-
 // Graph defines implements the business logic for Service.
 type Graph struct {
 	config                   *config.Config