Use cached data to find completed programs on LMS

These changes improve the performance of the LMS' program certification task. They also reduce strain on the programs service, especially when attempting to award program certificates to large numbers of students. ECOM-4490.

lms/djangoapps/learner_dashboard/tests/test_programs.py

@@ -56,8 +56,6 @@ class TestProgramListing(
     def _create_course_and_enroll(self, student, org, course, run):
         """
         Creates a course and associated enrollment.
-
-        TODO: Use CourseEnrollmentFactory to avoid course creation.
         """
         course_location = locator.CourseLocator(org, course, run)
         course = CourseFactory.create(

lms/djangoapps/learner_dashboard/views.py

@@ -11,7 +11,6 @@ from edxmako.shortcuts import render_to_response
 from openedx.core.djangoapps.credentials.utils import get_programs_credentials
 from openedx.core.djangoapps.programs.models import ProgramsApiConfig
 from openedx.core.djangoapps.programs import utils
-from student.views import get_course_enrollments
 
 
 @login_required
@@ -22,8 +21,7 @@ def view_programs(request):
     if not show_program_listing:
         raise Http404
 
-    enrollments = list(get_course_enrollments(request.user, None, []))
-    meter = utils.ProgramProgressMeter(request.user, enrollments)
+    meter = utils.ProgramProgressMeter(request.user)
     programs = meter.engaged_programs
 
     # TODO: Pull 'xseries' string from configuration model.