Add New Optional Parameters to AssistantRequest Struct (#795)

* Add more parameters to support Assistant v2

* Add goimports

assistant.go

@@ -70,6 +70,9 @@ type AssistantRequest struct {
 	FileIDs        []string               `json:"file_ids,omitempty"`
 	Metadata       map[string]any         `json:"metadata,omitempty"`
 	ToolResources  *AssistantToolResource `json:"tool_resources,omitempty"`
+	ResponseFormat any                    `json:"response_format,omitempty"`
+	Temperature    *float32               `json:"temperature,omitempty"`
+	TopP           *float32               `json:"top_p,omitempty"`
 }
 
 // MarshalJSON provides a custom marshaller for the assistant request to handle the API use cases