React Query API error handling

[CoenWarmer]

📝 Summary

React Query expects errors from an http fetching library to be in a certain form. Kibana's http is not a returning its error in the form that React Query likes, leading it to be difficult to show API error reason messages returned from the API inside Toasts.

An example of how it was implemented now is:

• https://github.com/elastic/kibana/blob/main/x-pack/plugins/observability/public/hooks/slo/use_fetch_global_diagnosis.ts#L61

This utility can be improved, and should be implemented in all React Query hooks in the Observability app to have a uniform experience.

Originally posted by @kdelemme in #157488 (comment)

✅ Acceptance criteria

• Investigate what RQ expects from a fetcher library
• Implement a global error handler with proper error message passing: Question Adbout Global Error Handlers TanStack/query#5099 (comment)
• Check all React Query hooks in Observability app so they all use the same pattern for error handling

[elasticmachine]

Pinging @elastic/actionable-observability (Team: Actionable Observability)