Spring Add createException method to ConvertibleClientHttpResponse in RestClient

retrieve() methods apply response status handling raising the appropriate RestClientResponseException. exchange() methods have a similar need, but must apply their own response status handling. Furthermore to decode the response body you need message converters, and there may be default status handlers configured on RestClient.Builder.

The motivation is very similar to #22825 for WebClient in 5.2. The same does not yet exist for RestClient. We can expose an additional method on ConvertibleClientHttpResponse to create a RestClientResponseException.

See https://github.com/spring-projects/spring-framework/issues/35375#issuecomment-3227725041 for more background on how the need for this came up.