Simplify debugging custom style files

[MisterAI]

In order to support the creation of user defined type it would be helpful to get some debug output whenever loading or applying a custom style file was loaded. Otherwise it is hard to know why the extension doesn't behave as expected. Maybe there is already such a debugging possibility but I couldn't find any so far.

Possible implementation:

1. User sets some CustomFileTypes.xml in the settings.
2. User starts debugging session
3. In the output window at "Debug" an error message appears, if applicable e.g.:
   • Graphical Debugging: Error loading type "NameSpace::Of::SomeC$lass"; invalid characters
   • Graphical Debugging: Didn't load type "NameSpace::Of::AnotherClass"; already defined

[awulkiew]

Yes, optional logging should be there.

[test544]

+1, debugging is hard now. I'm out of trying to make it work and will just make a copy of my structures with std::vector instead.
Other than that, it's a great plugin thank you.

A bit of offtop: would be nice of someone would come with solution for unreal engine's TArray<FVector2D>. The best i've come up was this, but alas. it doesn't work

  <Container Id="TArray" Type="TArray&lt;*&gt;">
    <Array>
      <Pointer>AllocatorInstance.Data</Pointer>
      <Size>ArrayNum</Size>
    </Array>
  </Container>