Flowable-rest module add/delete multiple instances execution API does not exist

[wu-weichao]

Is your feature request related to a problem? Please describe.

Flowable-rest module add/delete multiple instances execution API

In flowable-engine Include runtimeService.addMultiInstanceExecution and runtimeService.deleteMultiInstanceExecution function.

public Execution addMultiInstanceExecution(String activityId, String parentExecutionId, Map<String, Object> executionVariables) {
  return (Execution)this.commandExecutor.execute(new AddMultiInstanceExecutionCmd(activityId, parentExecutionId, executionVariables));
}

public void deleteMultiInstanceExecution(String executionId, boolean executionIsCompleted) {
  this.commandExecutor.execute(new DeleteMultiInstanceExecutionCmd(executionId, executionIsCompleted));
}

Hope to receive support in flowable-rest module.