Refactor browser dropdown links and components (#5562)

* refactor browser links and about modal

Moved about modal to separate component and added unit tests.

* refactor change password modal component

* added unit tests for ChangePasswordModal

* fix logout function in browser dropdown

* remove older unused BrowserDropdown component

* remove unused variables from BrowserDropdown component

* show BrowserDropdown and StorageInfo only for LoggedIn users

Non-loggedIn users will see a 'Login' button

browser/app/js/browser/Header.js

@@ -17,12 +17,27 @@
 import React from "react"
 import Path from "../objects/Path"
 import StorageInfo from "./StorageInfo"
+import BrowserDropdown from "./BrowserDropdown"
+import web from "../web"
+import { minioBrowserPrefix } from "../constants"
 
-export const Header = () => (
-  <header className="fe-header">
-    <Path />
-    <StorageInfo />
-  </header>
-)
+export const Header = () => {
+  const loggedIn = web.LoggedIn()
+  return (
+    <header className="fe-header">
+      <Path />
+      {loggedIn && <StorageInfo />}
+      <ul className="feh-actions">
+        {loggedIn ? (
+          <BrowserDropdown />
+        ) : (
+          <a className="btn btn-danger" href={minioBrowserPrefix + "/login"}>
+            Login
+          </a>
+        )}
+      </ul>
+    </header>
+  )
+}
 
 export default Header