Update BenchmarkDotNet to 0.14.0

[Numpsy]

refs #495

Updates BenchmarkDotNet to the latest 0.14.0 release, and extends the Expecto code to implement the new members of IConfig - no changes other than that.

The changes to the properties here probably make this count as a breaking API change, but if #501 is already a breaking change then perhaps that's an opportunity to do both at once?

(Note: I won't change the release notes etc here yet, as it'd probably just clash with #501)

[farlee2121]

Just merged #501, but I'll probably release it as a preview version first, since it's a breaking change

This PR makes sense to me conceptually, but I'll admit that I don't really know much about Expecto.BenchmarkDotNet.

I scanned the BenchmarkDotNet 14.0 release notes and our code. I didn't see any red flags. Is there anything else you were wanting to investigate before making this a full PR?

[Numpsy]

Is there anything else you were wanting to investigate before making this a full PR?

I'll have a look at adding a release note entry later, then activate it.

[Numpsy]

I don't really know much about Expecto.BenchmarkDotNet.

I want to try adding some new benchmarks to an existing Expecto test project, but I'm using UseArtifactsOutput in the build and BenchmarkDotNet 0.13 doesn't work with that - It's hopefully pretty straight forward, but I'll give it some more tests with a test or prerelease build

[Numpsy]

Does this need an entry in Migration notes as well as the release note? (anyone who is creating their own instances of BenchmarkConfig instead of using the default would have to populate the two new members)

[farlee2121]

Hmm. The changes seem pretty self explanatory. It's not nearly as disruptive as the fscheck 2 to 3 migration. The compiler warnings will likely tell people what they need to know.

[farlee2121]

This should be out with 11.0.0-alpha2