Answered Formname in MIGX Grid Columns

[{
    "formname":"3 Columns"
    ,"formtabs": [{
        "caption":"Section type"
        ,"fields": [{
            "field":"fake"
            ,"inputTVtype":"hidden"
        }
        ,{
            "field":"title"
            ,"caption":"The title of this section"
        }]
    },{
        "caption":"Column 1"
        ,"fields": [{
            "field":"title"
            ,"caption":"The title of this column"
        },{
            "field":"content"
            ,"caption":"The content of this column"
        }]
    },{
        "caption":"Column 2"
        ,"fields": [{
            "field":"title"
            ,"caption":"The title of this column"
        },{
            "field":"content"
            ,"caption":"The content of this column"
        }]
    },{
        "caption":"Column 3"
        ,"fields": [{
            "field":"title"
            ,"caption":"The title of this column"
        },{
            "field":"content"
            ,"caption":"The content of this column"
        }]
    }]
},{
    "formname":"2 Columns - image left"
    ,"formtabs": [{
        "caption":"Section type"
        ,"fields": [{
            "field":"fake"
            ,"inputTVtype":"hidden"
        }
        ,{
            "field":"title"
            ,"caption":"The title of this section"
        }]
    },{
        "caption":"Left column"
        ,"fields": [{
            "field":"solo_2_col_img_left_img"
            ,"caption":"Image in left column"
            ,"inputTV":"table_column-visibility-options"
        },{
            "field":"solo_2_col_img_left_img_alt"
            ,"caption":"Image in left column alt text"
            ,"inputTVtype":"image"
        }]
    },{
        "caption":"Right column"
        ,"fields": [{
            "field":"solo_2_col_list_items"
            ,"caption":"List items in the right column"
            ,"inputTV":"solo.list_items"
        }]
    }]
}]

[
{
    "header": "Section title",
    "width": "50%",
    "sortable": "true",
    "dataIndex": "title"
},
{
    "header": "Section type",
    "width": "50%",
    "sortable": "true"
    // "dataIndex": "What do I put here to get the name of the formname?"
}
]

[
{
    "header": "Section title",
    "width": "50%",
    "sortable": "true",
    "dataIndex": "section_title"
},
{
    "header": "Section type",
    "width": "50%",
    "sortable": "true",
    "dataIndex": "MIGX_formname"
}
]