chore(deps): Updated to Theia 1.39.0 (#2144)

- update Theia to `1.39.0`,
 - remove the application packager and fix the security vulnerabilities,
 - bundle the backed application with `webpack`, and
 - enhance the developer docs.

Co-authored-by: Akos Kitta <a.kitta@arduino.cc>
Co-authored-by: per1234 <accounts@perglass.com>

Signed-off-by: Akos Kitta <a.kitta@arduino.cc>

arduino-ide-extension/src/browser/theia/core/sidebar-bottom-menu-widget.tsx

@@ -7,7 +7,7 @@ import {
   injectable,
   postConstruct,
 } from '@theia/core/shared/inversify';
-import * as React from '@theia/core/shared/react';
+import React from '@theia/core/shared/react';
 import { accountMenu } from '../../contributions/account';
 import { CreateFeatures } from '../../create/create-features';
 import { ApplicationConnectionStatusContribution } from './connection-status-service';