Adds student attendances to show page

[ghatighorias]

This PR give the student show page an overview of her attendance to all classes grouped by terms

[coveralls]

Coverage increased (+0.02%) to 86.265% when pulling 5af6529 on ghatighorias/add_student_attendances_to_show_page into 40b4800 on master.

[ghatighorias]

Where condition is changed to user student from attendance. the reason is that a class has many attendance and filtering based on offered_course.student_id does not mean that the correct attendance is loaded too. it just mean the first attendance is loaded

[coveralls]

Coverage increased (+0.02%) to 86.265% when pulling ace597e on ghatighorias/add_student_attendances_to_show_page into 40b4800 on master.