Add function calling example

[alirezaalj]

Please provide examples for function calling as well
or provide a reference if there is documentation
of course documentation is not enough to use and reference for java code
iv tryed some examples but there is errors

    fun aiFuncCalling() {
        // Define function tool
        val weatherFunction = ChatCompletionTool.builder()
            .type(JsonValue.from("function"))
            .function(
                FunctionDefinition.builder()
                    .name("getWeather")
                    .description("Get current temperature for provided coordinates in celsius.")
                    .parameters(
                        FunctionParameters.builder()
                            .putAdditionalProperty("type",JsonValue.from("object"))
                            .putAdditionalProperty("latitude", JsonValue.from("number"))
                            .putAdditionalProperty("longitude", JsonValue.from("number"))
                            .build()
                    )
                    .strict(true)
                    .build()
            )
            .build()

        // Create request
        val createParams = ChatCompletionCreateParams.builder()
            .model(ChatModel.GPT_4O)
            .maxCompletionTokens(2048)
            .addUserMessage("What's the weather like in Paris today?")
            .addTool(weatherFunction)
            .toolChoice(ChatCompletionToolChoiceOption.Auto.AUTO) // Allow AI to call the function
            .build()

        // Send request
        val response = openAIClient.chat().completions().create(createParams)

        // Handle response
        response.choices().forEach { choice ->
            val message = choice.message()
            println("Assistant: ${message.content()}")
            message.toolCalls().stream().forEach{ toolCall ->
                if (toolCall[0].function().name() == "getWeather") {
                    val params = toolCall[0].function().arguments()
                    println("Function Call Detected: getWeather with params $params")

                }
            }
        }
    }

Exception in thread "main" com.openai.errors.BadRequestException: 400: OpenAIError{additionalProperties={error={message=Invalid schema for function 'getWeather': In context=(), 'additionalProperties' is required to be supplied and to be false., type=invalid_request_error, param=tools[0].function.parameters, code=invalid_function_parameters}}}
	at com.openai.core.handlers.ErrorHandler$withErrorHandler$1.handle(ErrorHandler.kt:45)
	at com.openai.services.blocking.chat.CompletionServiceImpl.create(CompletionServiceImpl.kt:59)
	at com.openai.services.blocking.chat.CompletionService.create$default(CompletionService.kt:28)
	at ca.dealertuoch.demos.spring.demoaikt.service.OpenAiCompletionService.aiFuncCalling(OpenAiCompletionService.kt:68)
	at ca.dealertuoch.demos.spring.demoaikt.CompletionsExampleKt.main(CompletionsExample.kt:19)

Process finished with exit code 1

[TomerAberbach]

I'm writing an example here: #213

But note that it'll get easier later once we implement #139

[TomerAberbach]

This is now merged