Static test context should not be used within instance methods

[Evangelink]

Summary

Assembly/Class initialize methods accept a TestContext instance as parameter. It's possible that some developers store this context in a field/property and then use this static instance in TestInitialize/TestCleanup, Dispose/DisposeAsync, in test methods or in methods providing arguments for parameterized tests. In the cases listed above, the user should instead use the instance TestContext property as it will contain up-to-date info related to current test while the static one will have only global information.

This rule should be enabled by default as Info as it won't cause any break to users but is definitely leading to some headache. On v4, we should consider bumping the severity to Warning.

Category of the rule should be usage.

Relates to #2051

AB#1986693