feat: add start and trigger savepoint routes

internal/managed_job/savepoint.go

@@ -80,3 +80,12 @@ func (job ManagedJob) trackSavepoint() error {
 
 	return nil
 }
+
+func (job ManagedJob) TriggerSavepoint() error {
+	err := job.createSavepoint()
+	if err != nil {
+		return err
+	}
+	err = job.trackSavepoint()
+	return err
+}