Fix invisible progress bars

[ihalaij1]

Description

What?

Fix invisible progress bars.

How?

Added new progress bar CSS classes with a aplus- prefix. Renamed the progress bar HTML class attributes with a aplus- prefix.

Fixes #1390

Testing

What type of test did you run?

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

Checked that the progress bars now appear correctly.

Did you test the changes in

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