Fix edit of PageProvider result tables in Studio Designer

Uncaught (in promise) TypeError: this._findGrid is not a function
    _hasGrid https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3014
    _insertElement https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3014
    _insertElement https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3825
    _addAtDOM https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3825
    _addAtDOM https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3825
    _transform https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3014
    promise callback*_transform https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3014
    _addAtDOM https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3825
    execute https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3014
    promise callback*updateModel/n.execute< https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3014
    execute https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3825
    updateModel https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3014
    apply https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3014
    executeCommand https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:1238
    _executeCommand https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:8150
    _updateView https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:8150
    V https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:2734
    w https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:2734
    _propertiesChanged https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:2734
    _flushProperties https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3816
    _invalidateProperties https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:2734
    set https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:3816
    _onItemEdit https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:8150
    r https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:2734
    fire https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:2734
    _edit https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:5569
    r https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:2734
    R https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:1670
    H https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:1670
    click https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:1670
    M https://connect.nuxeo.com/nuxeo/designer/nuxeo-view-designer.bundle.js:1670
nuxeo-view-designer.bundle.js:3014:31141