Removed all references to the student

[wotwot563]

Description

The project referenced the id from the identity server as the student id, this was wrong and is now replaced by identityid.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• My code follows the style guidelines of this project
• I did not update API Controllers, if I did, I added/changed Postman tests
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I updated the changelog with an end-user readable description
• I assigned this pull request to the correct project board to update the sprint board

Steps to Test or Reproduce

Outline the steps to test or reproduce the PR here.
These steps will be used during release testing.

1. Search for student in the project.

Link to issue

Closes: #145

[Brend-Smits]

Description
A few sentences describing the overall goals of the pull request's commits.

[Brend-Smits]

Thanks!