Implement Participant page using DataTables. Fix circular import in d…

[sayravai]

…ev environment.

Description

Implement the Participants page using the DataTables plugin, like in the All Results page. Has a lot better performance on large courses as there are no menus for adding user tags on each row, but instead a simple button which opens a dialog. Also the user tags are not transferred as HTML snippets from the backend, but instead a list of slugs and ids. Buttons to add/remove student tags for selected students are added as well.

This PR also contains a fix for a frequently appearing circular import issue in the development environment.

It also contains a change for the base.html, as browsers were complaining about the preloaded translation files. They are now marked as prefetch instead of preload.

Testing

Only manually tested to get this into production quickly. There are some inline CSS styles that need to be moved into a more proper place, but this can be done in the next minor update.

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

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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.

[ADD A DESCRIPTION ABOUT WHAT YOU TESTED MANUALLY]

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.
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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

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[ihalaij1]

Looks great!

I made some minor improvements and noticed two small issues.

• If clicking "Reset filters" button, it also unselects the "Active" filter, even though that is selected by default when loading the page.
• If you remove a student using the "Remove" button, the numbers in "Active" and "Removed" filter buttons do not update until the page is refreshed.

[sayravai]

Looks great!

I made some minor improvements and noticed two small issues.

• If clicking "Reset filters" button, it also unselects the "Active" filter, even though that is selected by default when loading the page.
• If you remove a student using the "Remove" button, the numbers in "Active" and "Removed" filter buttons do not update until the page is refreshed.

Thanks for the comments, these issues have now been fixed.

[ihalaij1]

Nice!