docs: use ErrorInfo type consistently in catchError docs (#91744)
## Summary
- Replace inline types with `ErrorInfo` in all TSX examples in
`catchError.mdx`
- Merge separate `import type { ErrorInfo }` into single import
statement
- Remove broken `highlight` attributes from "Recovering from errors"
code blocks
- Stop aliasing `unstable_retry` to `retry` — use `unstable_retry`
directly in all examples
- Use "children" instead of "contents" in error boundary descriptions
(`catchError.mdx`, `error.mdx`)