BUGFIX: Union type handling

[mficzel]

Demonstrate broken union types from annotations via test.

1. commit - remove rule that tests union types only with php 8 ... all green
2. commit - add a method with union type parameter hints and test thererfore ... still green
3. commit - add a class similar to 2. but with @param and @return annotations instead of type-hints ... tests verify that the same types are detected as with type hints ... and fail

Please note tha added case parameterB1 is equel to parameterB but demonstrates the different handlung of spaces in annotations that lead to detecting mixed type.

see: #3440

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Checklist

• Code follows the PSR-2 coding style
• Tests have been created, run and adjusted as needed
• The PR is created against the lowest maintained branch
• Reviewer - PR Title is brief but complete and starts with FEATURE|TASK|BUGFIX
• Reviewer - The first section explains the change briefly for change-logs
• Reviewer - Breaking Changes are marked with !!! and have upgrade-instructions

[mficzel]

I think ...

1. the @param annotation should be read with a regex and not explode( ' ', ...)
2. the expanType in the reflectionService has to learn about UnionTypes and probably intersectioTypes

[kdambekalns]

In PHP FQCN in strings never have a leading backslash – should we handle that the same way? At least consistency would be great, seeing the next test expects those without a leading backslash…

[mficzel]

The tests just took what the type hints created for granted. May aswell be buggy.

[kdambekalns]

See earlier comment about leading backslash…