This effectively evaluates the flag outside of the context of a course.
This was previously available through `.is_enabled_without_course_context`,
which has been removed in favor of simply `is_enabled()`.
This was done to make the CourseWaffleFlag interface more uniform with
that of WaffleFlag and ExperimentWaffleFlag and eliminate unecessary
branching when handling CourseWaffleFlags.
For the Courseware MFE rollout experiment, we want users'
default buckets to be consistent across course runs.
ExperimentWaffleFlag advised that this could be done
by calling `.is_enabled(...)` without a course_key argument;
however, doing so breaks when uing the main_flag.BUCKET_NUM
scheme to apply bucket rules for a specific set of users
or courses.
This commit explicitly adds course-unaware-bucketing via
a new kwarg to ExperimentWaffleFlag.__init__ method.
Furthermore, it fixes ExperimentWaffleFlag.is_enabled(course_key=None)
to work as advertised, by means of calling
.is_enabled_without_course_context on its subordinate flags.
TNL-7405
Now in addition to enrollment_start support in ExperimentWaffleFlag,
you can set an enrollment_end date for your experiment. All enrollments
after this date will get the control experience.
If the user is not logged in, the ExperimentWaffleFlag code was
raising an exception when trying to send an event to segment.
This is a quick fix to ignore anonymous users.
This is a helpful class when running an experiment, to help
bucket users and keep track of which enrollments to consider
as part of the experiment.
AA-53
