Fix step definition attribute support for the Visual Studio Extension

[tzongithub]

The generalization and simplifications of the handling of step definition attributes in #1938 break the analysis of the bindings in the Visual Studio Extension. In the Visual Studio Extension the step definition attributes are analyzed from the source code of the binding classes. Hence the binding reflection is not based on compiled/runtime types.

The TechTalk.SpecFlow.Bindings.Reflection.IBindingType instances returned by the Visual Studio Extension are not RuntimeBindingTypes and do not implement the IPolymorphicBindingType interface. As long as the extension works with source code constructs in the binding analysis this has to be taken into account.

The usage of the extension method BindingReflectionExtensions.IsAssignableFrom can be especially misleading, because it looks very similar to a System.Type.IsAssignableFrom call, but the semantics are not the same. Especially if the IBindingType is not an IPolymorphicBindingType, because then the extension method only compares the FullName of the types without being able to take polymorphism/inheritance into account.

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• Performance improvement
• Refactoring (so no functional change)
• Other (docs, build config, etc)

Checklist:

• I've added tests for my code. (most of the time mandatory)
• I have added an entry to the changelog. (mandatory)
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[SabotageAndi]

From the coding looks good for me. If all tests are still green and it solves your issue, you can merge it.