Fix "in progress" and "error" states of UpdateStatus component

This bug was likely introduced when upgrading to React Router 6. The `UpdateStatus` component needed access to the router's state in order to block navigation (and show a confirmation dialog to the user) when there are unsaved changes. With the upgrade to React Router 6, this required wrapping class components in a custom `withRouter` HOC. The `UpdateStatus` component exposes the different states (`SUCCESS`, `ERROR`, `IN_PROGRESS`) as static class fields (e.g. `UpdateStatus.IN_PROGRESS`). When wrapping the component in `withRouter`, those static class fields aren't forwarded, i.e. `UpdateStatus.IN_PROGRESS` is undefined.

However, at the moment, blocking navigation isn't possible anyway (at least temporarily), as React Router v6 has removed support for relevant features required to implement this (although it will hopefully return soon [1]). So for now, I have simply removed `withRouter` altogether. Once blocking navigation is possible again, we should refactor this component to a function component and use the hooks provided by React Router.

[1] remix-run/react-router#8139

ui/src/components/common/UpdateStatus.jsx

@@ -2,14 +2,10 @@
 //  future support is planned in future v6 releases
 //  see https://reactrouter.com/docs/en/v6/upgrading/v5#prompt-is-not-currently-supported for reference
 
-import React, { PureComponent } from 'react';
-import { compose } from 'redux';
+import { PureComponent } from 'react';
 import { defineMessages, injectIntl } from 'react-intl';
-// import { Prompt } from 'react-router';
 import { Intent, Spinner, Tag } from '@blueprintjs/core';
 
-import withRouter from 'app/withRouter';
-
 const messages = defineMessages({
   status_success: {
     id: 'entity.status.success',
@@ -100,4 +96,4 @@ class UpdateStatus extends PureComponent {
   }
 }
 
-export default compose(withRouter, injectIntl)(UpdateStatus);
+export default injectIntl(UpdateStatus);