fix: Improve alias handling in client generation

[WIStudent]

📝 Description

See #1760 for a description of the problem this PR tries to fix.

I first created the new test case and then worked through the code to figure out where ComplexObject was wrongly deduplicated. verifySelectionSet in generateTypeName.kt came to the conclusion, that

  first: complexObjectQuery {
    nameA: name
  }

and

  second: complexObjectQuery {
    nameB: name
  }

contain the same fields although they do not. Using selection.alias (if it exists) instead of selection.name in calculateSelectedFields fixed the issue.

🔗 Related Issues

fixes #1760

[dariuszkuc]

Thanks for the fix!