Fix user tagging for a single course participant.

[sayravai]

Description

Fix multiple issues with adding and removing user tags when on the single participants' page (/teachers/participants/x):

• Added tags did not appear on the page immediately due to js errors
• Removed tags did not appear on the "Add new tagging" dropdown menu (this feature was not present but now added)
• Used the aplus-button styling with the "xs" variant to more closely match the action buttons to the tags in the user_results.html template. This also allows keyboard navigation to work properly for the dropdown.

NOTE: This update also needs a patch to django-colortag to support adding custom css classes ("btn aplus-button--default aplus-button--xs") for the dropdown button.

Testing

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Translation

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[ihalaij1]

Great!

I tested this and made some minor changes.