[RunVSTest] Some test display names cause failures

To repro:

dotnet new mstest
dotnet add package Microsoft.Build.RunVSTest --prerelease

Then add this test:

[TestClass]
public class UnitTest1
{
    [DataTestMethod]
    [DataRow("Something error:")]
    public void TestMethod1(string errorMessage)
    {
        Assert.IsNotNull(errorMessage);
    }
}

Output:

RUNVSTESTTASK : Passed TestMethod1 (Something error : ) [< 1 ms]

The test actually passes though, and you can see this by running dotnet test:

It seems like something about "Something error:" being in the test "name" (data tests have the data in the names by default) which is causing something to interpret the console spew as an error.

@novacole

Reproduce the issue with the shown MSTest project, Microsoft.Build.RunVSTest prerelease package, and the data row containing a colon; compare its output with dotnet test. Start by tracing how the RunVSTest task interprets test display names and console output. Done means the test is reported as passed without treating the display name as an error.