New grade item is not created in D2L when LTI 1.3 LMS assignment is launched

In the LTI 1.1 version of Hypothesis, when an instructor creates and launches a new Hypothesis assignment in D2L a grade item for that assignment is created automatically. This allows Hypothesis to integrate with the D2L gradebook and enables the Hypothesis grading bar.

With our LTI 1.3 version, however, this grade item must be created and added manually by the instructor to each new assignment before the Hypothesis gradebook integration can be used.

A looming issue is that D2L's [New Content Experience](https://community.brightspace.com/s/article/The-New-Content-Experience-in-Brightspace) removes the ability for instructors to manually create grade items. D2L does currently provide a way to turn on and off the New Content Experience, but not all schools or D2L admins may have this option configured.

This means that for schools which have turned on the New Content Experience and do not allow instructors to enable/disable it, it is impossible for instructors to use Hypothesis' D2L gradebook integration and the Hypothesis grading bar.

Ideally, our LTI 1.3 tool should behave as the LTI 1.1 tool does, by transparently creating a grade item automatically for each new assignment that is launched.