[web] Drop Sidebar.OpenButton component

Because the use case [1] for which it was introduced was already gone:
to provide a link for directly opening the sidebar from a text teaching
the user where to find page related actions.

We can bring back the component if needed, but let's get rid of it now.

This commit "reverts" f1a56eb, df85b3c, and f39f65d

[1] #500

web/src/components/core/Sidebar.jsx

@@ -23,19 +23,15 @@ import React, { useEffect, useRef, useState } from "react";
 import { Button, Text } from "@patternfly/react-core";
 import { Icon, AppActions } from "~/components/layout";
 
-// FIXME: look for a better way to allow opening the Sidebar from outside
-let openButtonRef = {};
-
 /**
  * Agama sidebar navigation
  * @component
  *
  * @param {object} props
  * @param {React.ReactElement} props.children
  */
-const Sidebar = ({ children }) => {
+export default function Sidebar ({ children }) {
   const [isOpen, setIsOpen] = useState(false);
-  openButtonRef = useRef(null);
   const closeButtonRef = useRef(null);
 
   const open = () => setIsOpen(true);
@@ -91,7 +87,6 @@ const Sidebar = ({ children }) => {
     <>
       <AppActions>
         <button
-          ref={openButtonRef}
           onClick={open}
           className="plain-control"
           aria-label="Show navigation and other options"
@@ -134,23 +129,4 @@ const Sidebar = ({ children }) => {
       </nav>
     </>
   );
-};
-
-/**
- * Button for opening the sidebar
- * @component
- *
- * @param {object} props
- * @param {onClickFn} [props.onClick] - On click callback
- * @param {React.ReactElement} props.children
- */
-Sidebar.OpenButton = ({ onClick: onClickProp, children }) => {
-  const onClick = () => {
-    if (onClickProp !== undefined) onClickProp();
-    openButtonRef.current.click();
-  };
-
-  return <Button variant="link" isInline onClick={onClick}>{children}</Button>;
-};
-
-export default Sidebar;
+}