Improve e2e testing coverage and robustness

[reppuli92]

Description

What?

Improved the e2e test suite by adding a couple new testcases and fixing an error where the main navigation links would sometimes not work

Why?

To improve testing coverage and make the tests not fail

How?

I updated 2 test cases to remove errors, added more testing to 2 test files and created two helper files for a file upload exercise test.

Testing

Remember to add or update unit tests for new features and changes.

• How to test your changes in A-plus
• How to test accessibility

What type of test did you run?

• Accessibility test using the WAVE extension.
• Django unit tests.
• Selenium tests.
• Other test. (Add a description below)
• Manual testing.

I ran the Playwright e2e test suite several times to verify that the tests work now

Did you test the changes in

• Chrome
• Firefox
• This pull request cannot be tested in the browser.

Think of what is affected by these changes and could become broken

Translation

• Did you modify or add new strings in the user interface? (Read about how to create translation)

Programming style

• Did you follow our style guides?
• Did you use Python type hinting in all functions that you added or edited? (type hints for function parameters and return values)

Have you updated the README or other relevant documentation?

• documents inside the doc directory.
• README.md.
• Aplus Manual.
• Other documentation (mention below which documentation).

Is it Done?

• Reviewer has finished the code review
• After the review, the developer has made changes accordingly
• Customer/Teacher has accepted the implementation of the feature

Clean up your git commit history before submitting the pull request!

[ihalaij1]

Nice!