this creates a "plugin" that allows an account to choose
assignment properties that can be locked when a course is
copied
Test Plan:
* enable the plugin for an account
* create an assignment and set it to be locked on copy
* copy the course to another course
* as an admin of the account you should still be able to edit the assignment
* as a non-admin teacher of the course you should not be able to edit the frozen properties
refs #7931
Change-Id: I61d5dbfdf10f8f7519f8db06449b14ef5e7b8454
Reviewed-on: https://gerrit.instructure.com/10190
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Cody Cutrer <cody@instructure.com>
Bracken Mosbacker