Support sharing application errors (build, linters, analyzers, etc.) with guests

[dsplaisted]

Product and Version: VS and VS Code
OS Version: Windows and Mac OS
Live Share Extension Version: 0.2.133.57639 on VS
Target Platform or Language: .NET

Steps to Reproduce / Scenario:

1. Share a project that uses XUnit from VS to VS Code
2. Write a public method in a test class without putting a Fact attribute on it.
3. You should get an error from the XUnit analyzers saying that you need a Fact attribute on the method.

EXPECTED: XUnit analyzer error is show on guest VS Code instance
ACTUAL: No error shown in VS Code

[lostintangent]

@dsplaisted Thanks for the feedback! We've been tracking this work alongside #48, but as you mentioned, errors are much broader than just build, so it makes sense to have a separate work item. Additionally, we need to support the equivalent experience in VS Code, so I'll generalize this issue, and we can use it to track progress moving forward.

[srivatsn]

We'll need to make sure that the squiggles in the editor are also synced (since atleast in VS the mechanism for the squiggles and error list are disjoint)

[lostintangent]

@srivatsn Good point! I just updated the title to be even more general, since the context we want to share is errors, and the expected impact on the guests-side is a populated error list and editor squiggles.

[lostintangent]

Since the repro steps in this bug are specific to XUnit, and we've had another bug filed for the general issue of not sharing errors, I'm going to close this in favor of a new bug that can be the catch-all for this feature request (#165).

I referenced this bug and #141 from the new issue, but let me know if I didn't capture any of the details correctly. Thanks again for reporting this!