change exercise reference prefix for external and Welsh GOV

[KoWeiJAC]

What's included?

Closes #2483

Who should test?

✅ Product owner
✅ Developers
✅ UTG

How to test?

• Go to the preview link:
• The exercise table should sort by the number part of reference number
• Create a JAC exercise, the reference number should had JAC prefix
• Create a Welsh government exercise, the reference number should had GOW prefix

- Create a external exercise, the reference number should had `EXT` prefix

Risk - how likely is this to impact other areas?

🟢 No risk - this is a self-contained piece of work

Additional context

Include screen grabs, video demo, notes etc.

Related permissions

Have permissions been considered for this functionality?

• No permission changes required
• Permissions have been added / updated. Details:

---

PREVIEW:DEVELOP
can be OFF, DEVELOP or STAGING

[github-actions]

Visit the preview URL for this PR (updated for commit a307ee5):

https://jac-admin-develop--pr2514-feat-admin-2483-mech-j8ve5bae.web.app

_{(expires Thu, 29 Aug 2024 14:54:39 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

_{Sign: 4e92cf51659207b0ae3509dc5c40edde50edfec0}

[NormaJAC]

Both exercises have the expected prefixes.

[nickaddy]

@MattHowley I'm happy with this solution, but just to point out that you cannot retrospectively change the prefix, i.e. if you change your answer to Is this a Welsh Government exercise? later, the prefix won't change. If you made a mistake, you'd just delete the exercise and create a new one. Is that OK? I'm not convinced it's worth spending additional time on that, now that we have a working solution.

[MattHowley]

@MattHowley I'm happy with this solution, but just to point out that you cannot retrospectively change the prefix, i.e. if you change your answer to Is this a Welsh Government exercise? later, the prefix won't change. If you made a mistake, you'd just delete the exercise and create a new one. Is that OK? I'm not convinced it's worth spending additional time on that, now that we have a working solution.

Totally agree @nickaddy - not an issue if it's locked in from the off and, if a mistake occurs, recreate as you say.

[nickaddy]

@KoWeiJAC I've observed that if you retrospectively change the exercise type, e.g. from JAC to external, the prefix doesn't change. I've discussed with Matt and we agree that's OK, we are content with this solution.