Use ReactDOM.unstable_renderSubtreeIntoContainer in Modal/Popover/etc. Fixes broken <Links>

frontend/src/metabase/components/BodyComponent.jsx

@@ -26,7 +26,9 @@ export default ComposedComponent => class extends Component {
 
     _render() {
         this._element.className = this.props.className || "";
-        ReactDOM.render(<ComposedComponent {...this.props} className={undefined} />, this._element);
+        ReactDOM.unstable_renderSubtreeIntoContainer(this,
+            <ComposedComponent {...this.props} className={undefined} />
+        , this._element);
     }
 
     render() {

frontend/src/metabase/components/Modal.jsx

@@ -58,7 +58,7 @@ export default class Modal extends Component {
     _renderPopover() {
         const { backdropClassName, isOpen, style } = this.props;
         const backdropClassnames = 'flex justify-center align-center fixed top left bottom right';
-        ReactDOM.render(
+        ReactDOM.unstable_renderSubtreeIntoContainer(this,
             <ReactCSSTransitionGroup transitionName="Modal" transitionAppear={true} transitionAppearTimeout={250} transitionEnterTimeout={250} transitionLeaveTimeout={250}>
                 { isOpen &&
                     <div key="modal" className={cx(backdropClassName, backdropClassnames)} style={style}>

frontend/src/metabase/components/Popover.jsx

@@ -152,18 +152,17 @@ export default class Popover extends Component {
         if (this.props.isOpen) {
             // popover is open, lets do this!
             const popoverElement = this._getPopoverElement();
-            ReactDOM.render(
-              <ReactCSSTransitionGroup
-                transitionName="Popover"
-                transitionAppear={true}
-                transitionAppearTimeout={250}
-                transitionEnterTimeout={250}
-                transitionLeaveTimeout={250}
-              >
-                {this._popoverComponent()}
-              </ReactCSSTransitionGroup>
-              , popoverElement
-            );
+            ReactDOM.unstable_renderSubtreeIntoContainer(this,
+                <ReactCSSTransitionGroup
+                    transitionName="Popover"
+                    transitionAppear={true}
+                    transitionAppearTimeout={250}
+                    transitionEnterTimeout={250}
+                    transitionLeaveTimeout={250}
+                >
+                    {this._popoverComponent()}
+                </ReactCSSTransitionGroup>
+            , popoverElement);
 
             var tetherOptions = {};