Add basic static testing
>>> [!note] Migrated issue
<!-- Drupal.org comment -->
<!-- Migrated from issue #3563017. -->
Reported by: [theodorosploumis](https://www.drupal.org/user/869224)
>>>
<h3 id="summary-problem-motivation">Basic testing</h3>
<p>- Add gitlab CI yml (see issue <a href="https://www.drupal.org/project/human_decimal/issues/3459523">3459523</a>)<br>
- phpstan<br>
- phpcs<br>
- cspell</p>
> Related issue: [Issue #3459523](https://www.drupal.org/node/3459523)
issue