♻️ Move API errors to localized enum

[esizer]

♻️ Debt/Refactor

Send actual error messages, using the request locale from our API.

🕵️ Details

Once the tickets blocking this are completed, everything will be in place to send actual localized error messages from our graphql API. This will have several benefits:

• There will be one source of truth for error messages
• We no longer need to translated errors on the client meaning they won't be bundled with our app so fewer bytes sent to users
• Error messages can finally be part of our translation CI checks meaning no more missed translations

🙋‍♀️ Proposed Solution

• Create a localized enum for error codes
• Move client messages to new localized enum
• Update all of our current error codes to use the new localized enum

🌎 Localization

TBD...maybe?

✅ Acceptance Criteria

• [ ] Localized api error code enum created
• [ ] URQL error exchange can handle the new localized messages
• [ ] Error messages are on the backend
• [ ] API returns actual error messages
• [ ] PHP unit tests updated to use new localized messages

🛑 Blockers

### Blocked By
- [ ] https://github.com/GCTC-NTGC/gc-digital-talent/issues/11338

[github-actions[bot]]

Status: Error :warning:

Issues blocking this PR:

• NaN :warning: Issue/PR not found

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  This comment was automatically written by the Blocking Issues bot, and this PR will be monitored for further progress.