Runtime: Enable disabled xunit warnings

[stephentoub]

• [x] xUnit1019 MemberData must reference a member providing a valid data type
• [x] xUnit1026 Theory methods should use all of their parameters
• [x] xUnit2017 Do not use Contains() to check if a value exists in a collection

[danmosemsft]

Community folks, as indicated by the labels, this is a great first issue.

[ViktorHofer]

You are fast Mr Toub. Meanwhile I'm at an .NET Event giving a talk and watching your PRs coming in. I feel like a PM.

[Gnbrkm41]

working on 2000.

[Gnbrkm41]

a couple of the xUnit2003 errors from src/Common/tests/System/Security/Cryptography/AlgorithmImplementations/ECDsa/ECDsaTests.netcoreapp.cs slipped out somehow, after dotnet/corefx#39696: L193/L216

maybe I'll just do it whilst I'm doing this.

[Gnbrkm41]

....actually.... turns out that there's even more (well, 10). I started to wonder if the build sequence is somewhat flaky and misses some of the analyzers? I've had it happen a few times, where I had 500+ errors and building it again with some edits made all of them to disappear, despite the fact that I've fixed none. build -clean then rebuilding did fix the issue though.

[Gnbrkm41]

Attempting to grab 1026, if noone's working on it.

[stephentoub]

@Gnbrkm41, are you working on 1026? I started to and then noticed your comment. If you're actively working on it, I'll stop, otherwise I'll finish it up.

[Gnbrkm41]

@stephentoub, feel free to finish up; there's still quite a lot left to finish, and I probably won't have time to finish it up for now. Thanks!

[stephentoub]

All rules we plan to enable have been enabled. Thanks!

[Gnbrkm41]

Pretty amazing to see all of them enabled, Thanks everyone!