Feature/job (#65)

* Add the executor, plan node and mock for admin job.

* Add the plan for admin job sentence.

* Add the admin job testing.

* Fit the QueryContext.

* Let job sentence return parameters reference default.

* Move the resource to plan from sentence.

* Unify job sentence to string.

* Remove one unused header.

* Return error when malformed response/request in release running.

* Not move the sentence field.

* Fix the parser memory leak.

* Fix the non return error.

* Fix the header guard.

* Check job by function.

* Add executor time stat.

* Mark the explain unimplemented.