Added initial TagAttribute and Filter implementation

[esbenbach]

Added initial TagAttribute and Filter implementation

[esbenbach]

This still needs some work.

But basically just wanted to determine if the approach of having a DocumentFilter is the right way to go?

[esbenbach]

Yet another question. Is the idea that adding the TagAttribute to a controller should override the Tags on all the operations, or should it add to the existing operation tags. How about the default "ControllerName" tag that is added, should it be preserved?

[domaindrivendev]

The common use case we’re trying to solve for here is adding additional metadata to the default tag that’s assigned to each operation (controller name but can be overridden via TagActionsBy). So, I would avoid the additional operation filter as it adds complexity and could be a little confusing. Otherwise this looks awesome. Also, you might want to take a quick look at the XmlCommentsDocumentFilter in the SwaggerGen project. It’s doing something very similar.

[esbenbach]

I removed the operation filter. Took another look at the XmlCommentsDocumentFilter, and as far as i can tell it does things in a very similar matter as well. If you prefer I can change my implementation to follow the style of that filter, but personally i prefer the way I have arranged the code (but as always its just a matter of taste.)