Admission Contract - ValidModuleEntry

[NikoBergemann]

When a student submits an admission for Semester SS2020, but was only matriculated in 2016 it is currently a valid entry.
We need to fix this.

Possible solution? Parse the SemesterEntry at the moduleMatch in matriculationData and check with timestamp ???

[anemonekk]

What is the matriculationStatus in MatriculationData used for? Can't we maybe just check, if it is not null?
Otherwise, checking the timestamp sounds reasonable to me.