Teacher role selection

[volodymyrdovhan]

Hello,
as a recommendation and to improve the plugin flexibility, consider adding the Teacher role(s) selection in the plugin setting and replace the hard-coded 'editingtecher' shortname usage.

This will allow admins to setup custom roles as a teacher role for the plugin.

[juacas]

Two points:

• AFAIK, this query checks if a user has role "editingteacher" in any course. This kind of conditions is best served by permissions than roles. Can it be redesigned to check a permission? i.e. "moodle/grade:edit", or a custom capability like could be "mod/certifygen:requestteacheractivitycertificate"
• This check is done in Modole API with $courses = get_user_capability_course('mod/certifygen:requestteacheractivitycertificate', $user->id);