LC Task Can Fail Without Logging An Error

### Issue Description

Someone reported [here](https://dev.azure.com/devdiv/DevDiv/_workitems/edit/1242223) that the LC task can fail without throwing a warning.

```
Some times, when I rebuild my solution (C#) in Visual Studio Enterprise 2019, the following error is shown:

Severity Code Description Project File Line Suppression State

Error The “LC” task returned false but did not log an error. SBM

Other times, the solution simply builds without a problem.
```

ToolTaskExtension may be able to return false and not log an error. Note that the LC task does not implement its own execute function.