WD-2173 fix exam statuses

[usamabinnadeem-10]

Done

• Surface true exam statuses in credentials/your-exams

QA

• Check out this feature branch
• Run the site using the command ./run serve or dotrun
• View the site locally in your web browser at: http://0.0.0.0:8001/
  • Be sure to test on mobile, tablet and desktop screen sizes
• Buy an exam and schedule it
  • It should show Scheduled status with Reschedule button
• When you are at most 30 minutes from exam but haven't started yet
  • It should show Ready to be taken with Take Exam button
• When you start exam and during exam it should show In Progress with Continue exam button
• When you have submitted the exam it should show one of the following (according to exam state) with no button
  • Grading
  • Graded
  • Finalised
  • Completed
  • Processed
• When you haven't taken the exam within its effective window it should show Expired with no button
• If during the exam you open credentials/your-exams
  • It should show that exam as In Progress with Continue exam button visible

Issue / Card

Fixes 12173

Help

QA steps - Commit guidelines

[webteam-app]

Demo

Jenkins

demos.haus

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 74.12%. Comparing base (8064843) to head (b8e798a). Report is 13 commits behind head on main.

:exclamation: Current head b8e798a differs from pull request most recent head da1ed3a

Please upload reports for the commit da1ed3a to get more accurate results.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #13988 +/- ## ======================================= Coverage 74.12% 74.12% ======================================= Files 107 107 Lines 2864 2864 Branches 957 957 ======================================= Hits 2123 2123 Misses 715 715 Partials 26 26 ```

[linux-in-flux]

I don't think I can check this branch out with my permissions level to actually test this, but all of the messages and timings sound good. So long as we have verified that it will not show "In Progress" before the exam is actually in progress, all of the messages seem intuitive to me.