What does this mr do?

Whenever logging in on the development build, if no email address suffix is specified it automatically fills in the username and password. (usernames with email suffixes are not affected)

e.g. (username = "student1", password = "") -> (username = "student1@tudelft.nl", password = "student1")

This will speed up one of the repetitive tasks of queue development. No changelog needed because it only impacts the development build.

Does this MR meet the acceptance criteria?

• I have added a changelog entry to reflect the significant changes I made.
• Tests were created to test the feature.
• I have updated the documentation accordingly.
• I adhere to the style guide.

Closes #328 (closed)