refactor: system/CLI/BaseCommand.php

[mcsaygili]

Description
See #8732

• replace empty()
• add types

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

[mcsaygili]

Failed at PHPUnit / Others (8.3) / Sanity Tests (pull_request) step.
After adding .gitkeep file to /CodeIgniter4/writable/debugbar/ passed.
Should I add the .gitkeep ?

[kenjis]

Sorry, now PHPUnit checks fail.
It is addressed in #8740.

[kenjis]

I merged #8740.
Can you rebase this PR?
See https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/workflow.md#updating-your-branch
If you have questions, feel free to ask.

[kenjis]

See https://github.com/codeigniter4/CodeIgniter4/pull/8741/commits
Please remove all commits of mine.
See https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/workflow.md#updating-your-branch

[mcsaygili]

I tried using an IDE, but using the command line as you mentioned to be easier. Can you look into it?

[kenjis]

Thank you!

Leaning git commands is very useful. git commands are the only common language for Git.