fix: define of STDOUT in CLI init() method

[jozefrebjak]

Description

In development and also in production environment where composer dependencies are installed without --no-dev composer flag we can have an issue with running commands from Controller with command() helper.

Issue is there because of Psalm required package amphp/byte-stream in

functions.php

Psalm is often installed with devkit, so we need to check if STDOUT is already defined.

Fixes #7047

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[MGatner]

Thanks for the quick fix!

[kenjis]

Okay. Thanks!