`<FormattedMessage id=` should not be only entity name but also field

[jozef-slezak]

should be id="customer.createdAt" instead of id="Customer"

            { field: "avatarUrl", flex: 1, type: "string", valueFormatter: ({ value }) => value, renderHeader: (params: GridColParams) => (<FormattedMessage id="Customer" defaultMessage="avatarUrl"/>) },
            { field: "createdAt", flex: 1, type: "date", valueFormatter: ({ value }) => intl.formatDate(value), renderHeader: (params: GridColParams) => (<FormattedMessage id="Customer" defaultMessage="createdAt"/>) },

[mat-app]

To solve this issue we will need at least entity name as input into function that are adding column/widget into table/form. This should be handeled somehow by demo app.