Change dataExists to a bool and handle instances of Autorefresh where grabdatafordownload is not defined

ui/src/shared/components/AutoRefresh.js

@@ -156,7 +156,9 @@ const AutoRefresh = ComposedComponent => {
           lastQuerySuccessful,
           isFetching: false,
         })
-        grabDataForDownload(timeSeries)
+        if (grabDataForDownload) {
+          grabDataForDownload(timeSeries)
+        }
       })
     },
 

ui/src/shared/components/LayoutCell.js

@@ -59,7 +59,7 @@ class LayoutCell extends Component {
       <div className="dash-graph">
         <LayoutCellMenu
           cell={cell}
-          dataExists={celldata.length}
+          dataExists={!!celldata.length}
           isDeleting={isDeleting}
           isEditable={isEditable}
           onDelete={this.handleDeleteCell}

ui/src/shared/components/LayoutCellMenu.js

@@ -53,7 +53,7 @@ const LayoutCellMenuContainer = props => {
   return <LayoutCellMenu {...props} />
 }
 
-const {bool, func, shape, number} = PropTypes
+const {bool, func, shape} = PropTypes
 
 LayoutCellMenuContainer.propTypes = {
   isDeleting: bool,
@@ -62,7 +62,7 @@ LayoutCellMenuContainer.propTypes = {
   onDeleteClick: func,
   cell: shape(),
   isEditable: bool,
-  dataExists: number,
+  dataExists: bool,
 }
 
 LayoutCellMenu.propTypes = LayoutCellMenuContainer.propTypes