Add initializer to ChatFunctionCall to initialize from external with properties

Author: yoshiaki-yamada

Sources/OpenAI/Public/Models/ChatQuery.swift

@@ -61,6 +61,11 @@ public struct ChatFunctionCall: Codable, Equatable {
     public let name: String?
     /// The arguments to call the function with, as generated by the model in JSON format. Note that the model does not always generate valid JSON, and may hallucinate parameters not defined by your function schema. Validate the arguments in your code before calling your function.
     public let arguments: String?
+
+    public init(name: String?, arguments: String?) {
+        self.name = name
+        self.arguments = arguments
+    }
 }
 
 /// See the [guide](/docs/guides/gpt/function-calling) for examples, and the [JSON Schema reference](https://json-schema.org/understanding-json-schema/) for documentation about the format.