Function toOpenAIMessage

Returns
    | {
        content: string
        | { text: string; type: "text" }[];
        name?: string;
        role: "assistant";
        tool_call_id?: string;
        tool_calls?: {
            function: { arguments: string; name: string; [key: string]: unknown };
            id: string;
            type: "function";
        }[];
        [key: string]: unknown;
    }
    | {
        content: string
        | { text: string; type: "text" }[];
        role: "tool";
        tool_call_id: string;
        [key: string]: unknown;
    }
    | {
        content: string
        | null;
        name: string;
        role: "function";
        [key: string]: unknown;
    }
    | {
        content: | string
        | (
            | { text: string; type: "text" }
            | { image_url: { url: string }; type: "image_url" }
        )[];
        name?: string;
        role: "user";
        [key: string]: unknown;
    }
    | {
        content: string
        | { text: string; type: "text" }[];
        name?: string;
        role: "system";
        [key: string]: unknown;
    }
    | {
        content: string
        | { text: string; type: "text" }[];
        name?: string;
        role: "developer";
        [key: string]: unknown;
    }
    | null