♻️(frontend) improve handleAIError

To display the throttle error messages,
we are doing a condition on the error message
that we get from the backend.
It is error prone because the backend error
message are internationalized.
This commit fixes this issue.
It DRY the component as well.

CHANGELOG.md

@@ -20,6 +20,7 @@ and this project adheres to
 - 🐛(backend) require right to manage document accesses to see invitations #369
 - 🐛(i18n) same frontend and backend language using shared cookies #365
 - 🐛(frontend) add default toolbar buttons #355
+- 🐛(frontend) throttle error correctly display #378
 
 
 ## [1.6.0] - 2024-10-17