Resolve "Use preferences instead of managed group types for school structure"

Closes #20 (closed)

aleksis/apps/cursus/util/group_types.py

-from aleksis.core.models import GroupType
-
-from ..settings import SCHOOL_CLASS_GROUP_TYPE_NAME, SCHOOL_GRADE_GROUP_TYPE_NAME
-
-
-def get_school_grade_group_type():
-    group_type, __ = GroupType.objects.managed_by_app("cursus").get_or_create(
-        name=SCHOOL_GRADE_GROUP_TYPE_NAME, managed_by_app_label="cursus"
-    )
-    return group_type
-
-
-def get_school_class_group_type():
-    group_type, __ = GroupType.objects.managed_by_app("cursus").get_or_create(
-        name=SCHOOL_CLASS_GROUP_TYPE_NAME, managed_by_app_label="cursus"
-    )
-    return group_type