CLC-3164 Include deleted bCourses course sites in SIS ID check

https://jira.ets.berkeley.edu/jira/browse/CLC-3164

Canvas handles deletion of users, courses, and sections poorly from a UX point of view. The deleted records are invisible in the browser but their IDs will block creation of new records with the same IDs. This interferes with a fairly common workflow: "create a course site; work on it a bit; decide it would be simpler to start over; delete the course site; try to re-create it."

We don't have solutions for all possible scenarios along these lines, but for that particularly common scenario, this change (to skip IDs that belong to deleted course sites) unblocks Course Provisioning.