[API] Add description and location_address to course timetable events API

[dsweeney2]

We currently use the API to create timetable events for sections. We would like to add an HTML link to a zoom url in the description field, however, currently only title and location are available through this API: https://canvas.instructure.com/doc/api/calendar_events.html#method.calendar_events_api.set_course_ti... which don't allow HTML.

We have a large volume of data to send, so the ability to package up events in a single API call is critical. The events are not always in a predictable sequence, which is why we are using this particular end point.

An alternative would be to allow HTML in the location field.