Fix failing Razor file comparison tests

[ajaybhargavb]

Fixes https://github.com/aspnet/AspNetCore-Internal/issues/1601

It looks like OrderBy() is using a different default StringComparer between Windows and Linux which is why we were seeing failures only on Ubuntu CI. I've now specified the StringComparer and changed the ordering to match what is expected.

[ajaybhargavb]

Minimal repro,

static void Main(string[] args)
{
    var arr = new[] { "A", "B", "_" };
    Console.WriteLine(string.Join(", ", arr.OrderBy(a => a)));
}

outputs,
_, A, B on Windows
A, B, _ on Linux

@stephentoub, is there a reason for this inconsistency?

[stephentoub]

String comparison is by default culturally aware, and there's a difference in the culture data on Windows (coming from the OS) vs on Linux (coming from ICU).