add totalValueGetter to propCategories

[AnnMarieW]

Fix issue as reported on the forum

Sample app

import dash
from dash import html
import dash_ag_grid as dag
import pandas as pd

app = dash.Dash()


df = pd.read_csv(
    "https://raw.githubusercontent.com/plotly/datasets/master/ag-grid/olympic-winners.csv"
)

column_defs = [
    {"field": "country", "rowGroup": True, "hide": True},
    {"field": "year", "rowGroup": True, "hide": True},
    {"field": "gold", "aggFunc": "sum"},
    {"field": "silver", "aggFunc": "sum"},
    {"field": "bronze", "aggFunc": "sum"},
]

default_col_def = {
    "flex": 1,
    "minWidth": 150,
}

auto_group_column_def = {
    "minWidth": 300,
    "cellRendererParams": {
      #  "innerRenderer": "myInnerRenderer",
         "totalValueGetter": {"function": "myTotalValueGetter(params)"},
    },
}

app.layout = html.Div(
    [
        dag.AgGrid(
            id="grid",
            rowData=df.to_dict("records"),
            columnDefs=column_defs,
            defaultColDef=default_col_def,
            enableEnterpriseModules=True,

            dashGridOptions={
                "autoGroupColumnDef": auto_group_column_def,
                "groupTotalRow":"bottom",
                "grandTotalRow":"bottom",

            },            
        )
    ]
)

if __name__ == "__main__":
    app.run(debug=True)

var dagcomponentfuncs = window.dashAgGridComponentFunctions = window.dashAgGridComponentFunctions || {};
var dagfuncs = window.dashAgGridFunctions = window.dashAgGridFunctions || {};

dagfuncs.myTotalValueGetter = function (params) {
   console.log("value", params)
    const isRootLevel = params.node.level === -1;

        if (isRootLevel) {
          return 'Grand Total';
        }
        
        return `Sub Total (${params.value})`;
    }

dagcomponentfuncs.myInnerRenderer = function (props) {
    console.log("inner")
    const footer = props.node.footer;
    const isRootLevel = props.node.level === -1;
    const value = props.value;

    if (footer) {
        if (isRootLevel) {
            return React.createElement(
                "span",
                {
                    style: {
                        textDecoration: "underline",
                        fontWeight: "bold"
                    }
                },
                "Grand Total"
            );
        } else {
            return React.createElement(
                "span",
                {
                    style: {
                        textDecoration: "underline"
                    }
                },
                "Sub Total " + value
            );
        }
    }

    return React.createElement("span", null, value);
};