* LEARNER-8158
Fixed completion param issue
- There is a case where we are sending requested_fields in params as comma separated list
e.g. requested_fields=children,show_gated_sections,graded,special_exam_info,completion.
- We didn't test for this case in first place and test cases were sending requested_fields as list.
- Now we can also handle this comma separated completion field which was getting ignored before.
137a271fd2