`AreEqualCaseFailMsg` is currently dead code that is never reached

[Youssef1313]

testfx/src/TestFramework/TestFramework/Assertions/Assert.AreEqual.cs

Lines 1418 to 1430 in 56cacdd

	string finalMessage = !ignoreCase && CompareInternal(expected, actual, ignoreCase, culture) == 0
	? string.Format(
	CultureInfo.CurrentCulture,
	FrameworkMessages.AreEqualCaseFailMsg,
	userMessage,
	ReplaceNulls(expected),
	ReplaceNulls(actual))
	: string.Format(
	CultureInfo.CurrentCulture,
	FrameworkMessages.AreEqualFailMsg,
	userMessage,
	ReplaceNulls(expected),
	ReplaceNulls(actual));

At this point, CompareInternal(expected, actual, ignoreCase, culture) == 0 is clearly always false.

The corrected code would be CompareInternal(expected, actual, ignoreCase: true, culture) == 0. The original intent seems to produce a specialized message if the comparison isn't ignoring case, but expected and actual are differing by casing only.

@Evangelink Do you think we should follow the original intent? Or just keep the current behavior and delete the dead code?

AB#2331939

[Youssef1313]

Let's fix after #4476 is merged to avoid annoying merge conflicts