add type checking for object on rawData setter

[s3ttingz]

When fetching a newly created and empty pipeline via the getPipeline-method, the following error occurs:

"message": "property_exists(): Argument #1 ($object_or_class) must be of type object|string, array given",
"exception": "TypeError"

The pipedrive API returns

{
    "success": true,
    "data": {
        "id": 7,
        "name": "New Pipeline",
        "url_title": "New-Pipeline",
        "order_nr": 4,
        "active": true,
        "deal_probability": true,
        "add_time": "2024-09-14 12:02:41",
        "update_time": "2024-09-14 12:02:41",
        "selected": true,
        "deals_summary": []
    }
}

whereas a pipeline containing a deal returns a deals_summary object as seen here:

...
"deals_summary": {
    "per_stages": {
        "19": {
            "USD": {
                "count": 4,
                "value": 0,
                ...
            }
        }
    }
}