Pass query instead of slice to Action buttons to prevent lagging query (#1948)

* Pass query instead of slice to Action buttons to prevent lagging query

* Delete beforeOpen and put DisplayQueryButton in pure component

superset/assets/javascripts/explorev2/components/ChartContainer.jsx

@@ -254,6 +254,7 @@ class ChartContainer extends React.Component {
                 <ExploreActionButtons
                   slice={this.state.mockSlice}
                   canDownload={this.props.can_download}
+                  query={this.props.query}
                 />
               </div>
             </div>