Generate `DebuggerDisplayAttribute` for API

[TomFinley]

DebuggerDisplayAttribute is a nice little thing to add to classes -- properly written, they make the debugger a bit less obnoxious to use by putting some important information about an instance front and center. At the same time, it would be nice if we could possibly avoid having to write all those ourselves, piecemeal.

CSharpApi.cs is geneated from the code in CSharpApiGenerator.cs. It may be a simple matter to enhance that code to attach a DebuggerDisplay attribute to the generated classes. The configuration objects have their properties and documentation derived from the ArgumentAttribute. We needn't display everything: In other contexts, we have distinguished important vs. more unimportant "advanced" parameters by ArgumentAttribute's SortOrder property. We could exploit that for this purpose as well, and only include in the display formatted string those parameters with that property set and of course only those types that would display well there anyway.

[veikkoeeva]

DebuggerStepThrough could be relevant to skip unrelevant code in the debugger.

Relevant information for the curious:
https://blogs.msdn.microsoft.com/jaredpar/2011/03/18/debuggerdisplay-attribute-best-practices/
http://www.debuggerstepthrough.com/2013/01/some-good-to-know-c-attributes.html

[danmoseley]

Any interest in a contribution here @veikkoeeva ?

[veikkoeeva]

@danmosemsft Realistically on the first or second week of June I have more time. Unless it's OK to add attributes here and there, and someone giving places I haven't seen. But that could be someone else too, so let's not lock on me. :)

[danmoseley]

@veikkoeeva that would be welcome. I think that timeframe is fine. I'm sure @TomFinley can give pointers as required.

[jwood803]

@TomFinley Was just looking over this and I'm wondering, would the new API design impact this issue?

[codemzs]

With the new API in place with debugger view support.