Add Microsoft.SymbolUploader.Build.Task to WCF

[StephenBonikowsky]

Investigate if we need to port dotnet/corefx#27975

Based on Issue dotnet/corefx#27343

@dagood This was done in CoreFx back in March, I'm not sure off-hand how we publish our symbols, does it seem like something we need to do as well?

[dagood]

What this would do is let devs easily get symbols from the Microsoft symbol server(s) for any WCF daily build. I think there's a general guideline that this should be done, but ultimately I think it's up to you.

This doesn't affect the workflow for releases. Symbols for anything on nuget.org must be uploaded with an expiration time of 30 years, but this flow only uploads them for 180 days. There's manual processing that happens during a release (I've done this so far) that will still need to happen either way.

(Some of this is covered in https://github.com/dotnet/core-eng/issues/3382.)

[Lxiamail]

This issue is for tracking auto upload symbols for daily build, which doesn't have to be 3.0 goal.