Improve AttachVS gem output

[MarcoRossignoli]

I found useful have some output to understand if everything is good.

Let me know @nohwnd

We could ship this gem as nuget+source file with DebuggerHelper.AttachVisualStudioDebugger(string environmentVariable), inner loop for a project that spawns processes would be straightforward to debug(easier than https://devblogs.microsoft.com/devops/introducing-the-child-process-debugging-power-tool/ here we can jump into new repo/vs instance), I'm using it also with TE(I will propose AttachVisualStudioDebugger also there for our stuff) and it's a bit "magic" put bp on datacollector process and that's all 💘 💘 💘

[nohwnd]

Sure, I am usually using DebugView++ and the Debug output in VS to observe it, when it does not work as expected. But this might help as well.

[nohwnd]

we could ship this gem as nuget+source file with

Sure, I tried not to overcomplicate it. But there is room for improvement for sure.

I'm using it also with TE

TE should have it's own service that calls back to VS to attach processes (and is used when you ask testhost.exe to attach VS to it), so maybe that could be used.