Parse union types for circular dependency detection

[dereuromark]

Summary

• Add extractDtoNamesFromType() method that splits union types on | and extracts DTO names from each part
• Union types like UserDto|AdminDto are now correctly analyzed for circular dependencies

Fixes #85

Example

'Container' => [
    'fields' => [
        'item' => [
            'type' => 'ItemADto|ItemBDto', // Both types are now checked
        ],
    ],
],
'ItemA' => [
    'fields' => [
        'container' => ['type' => 'ContainerDto'], // This creates a cycle
    ],
],

Previously, the union type ItemADto|ItemBDto was not parsed, so the circular dependency Container -> ItemA -> Container was not detected. Now it is correctly detected.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.46%. Comparing base (72fd6ef) to head (9c14efe).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master      #86      +/-   ##
============================================
+ Coverage     83.42%   83.46%   +0.03%     
- Complexity     1382     1386       +4     
============================================
  Files            40       40              
  Lines          3336     3344       +8     
============================================
+ Hits           2783     2791       +8     
  Misses          553      553              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.