MNTR: make spec filtering more flexible

[Aaronontheweb]

Version: 1.4.18

The spec filtering we have for the MNTR today is not very well documented and is extremely brittle - i.e. I have to get the FQN of the method marked with MultiNodeFact spelled exactly right on the CLI. https://getakka.net/articles/testing/multi-node-testing.html#running-multi-node-tests

I would strongly prefer it if the spec argument scheme followed what NBench does, which allows wildcard include / exclude filtering rules for this purpose: https://nbench.io/articles/running.html#commandline-arguments

[Aaronontheweb]

So looks like the spec filtering method doesn't require an FQN, but it's still janky and needs to be better documented:

akka.net/src/core/Akka.MultiNodeTestRunner/Program.cs

Lines 230 to 237 in e7b3fb2

	if (!string.IsNullOrWhiteSpace(specName) &&
	CultureInfo.InvariantCulture.CompareInfo.IndexOf(test.Value.First().TestName,
	specName,
	CompareOptions.IgnoreCase) < 0)
	{
	PublishRunnerMessage($"Skipping [{test.Value.First().MethodName}] (Filtering)");
	continue;
	}