extension function for Chatclient.CalLResponseSpec.entity(Class<?>) a…

[joshlong]

this adds kotlin support for using the ChatClient to get typesafe responses back

val joke:Joke = cc
      .prompt("tell me a joke")
      .call()
      .entity<Joke>()
println(joke)

this is as opposed to the more verbose and less idiomatic Kotlin code without the extension function

val joke : Joke = cc
    .prompt("tell me a joke")
    .call()
    .entity(Joke::class.java)
```

[sdeleuze]

@joshlong Could you please use ParameterizedTypeReference instead of Class in order to avoid type erasure?

[sdeleuze]

See https://github.com/spring-projects/spring-framework/blob/main/spring-webflux/src/main/kotlin/org/springframework/web/reactive/function/client/WebClientExtensions.kt#L45 for an example

[sdeleuze]

Also please add an extension for responseEntity(...) as well.

[joshlong]

ive updated the PR accordingly. thanks for the great feedback

[markpollack]

merge in 944fb99