Types are no longer parsed by this library. We do now use the phpstan
parser to parse types. Having support for more advanced type definitions
without the burden to support all parser logic.

In this commit I do introduce support for:
- array shapes
- constant expressions like integers, strings and floats
- constant expressions for enums and class constants
- Callable support with and without params and return types.

A new set of unittests have been added to ensure everything keeps working as
expected.