As a developer, I want to fill in Affiliations field in DOI form so that the DOI form can be saved correctly in integration tests

[hannyle]

Describe the user story

In DOI form, Affiliations is now marked as a mandatory field for metax integration. Therefore, Cypress tests related DOI form need to be updated so they can pass successfully.
Related backend PR: CSCfi/metadata-submitter#399

Tasks:

• Fill in Affiliations field for cypress tests related to DOI form.

Testing

• Integration tests

#Definition of Done
All Cypress tests should be passed successfully.