switch arguments for expected and actual in Assert.AreEquals in multiple tests

[HeroMaxPower]

Description

This PR is to fix some asserts in the TestPlatform.sln solution, the expected and actual are round the wrong way.

e.g.

Assert.AreEqual(aggregator.RunContextAttachments.Count, 1, "RunContextAttachments List must have data.");

should be

Assert.AreEqual(1, aggregator.RunContextAttachments.Count, "RunContextAttachments List must have data.");

Related issue

Fixes #2328

[msftclas]

All CLA requirements met.

[HeroMaxPower]

I think i got all of them, i also converted
convert Assert.AreEqual(true, ... to Assert.IsTrue(
convert Assert.AreEqual(false, ... to Assert.IsFalse(
convert Assert.AreEqual(null, ... to Assert.IsNull(

Ready to review.

[nohwnd]

Merged, thanks!