Use Ordinal[IgnoreCase] string comparison

[jnyrup]

Unit tests should behave the same no matter the culture of the machine being run on.

• Microsoft.CodeAnalysis.FxCopAnalyzers
  • Helps find usages of methods where a StringComparison is not specified.
• Microsoft.CodeAnalysis.BannedApiAnalyzers
  • Used in conjuction with BannedSymbols.txt to prohibit usage of culture aware StringComparison and CultureInfo.

As netcoreapp2.1/netcoreapp3.0/netstandard2.1 has more string overloads than net47/netstandard2.0 I added some dummy overloads in SystemExtensions to satisfy the analyzers.

One large difference in behavior is that TryConversionStep now uses CultureInfo.Invariant instead of CultureInfo.CurrentCulture.

This fixes #1096
This closes #1184 (Thanks @kimsey0 for pushing this change forward)

[dennisdoomen]

So using ordinal case-insensitive for string comparisons should be another design guideline. Maybe we should add them to the PR template?

[jnyrup]

So using ordinal case-insensitive for string comparisons should be another design guideline. Maybe we should add them to the PR template?

Would fine be.
Nevertheless one should get a compile time error now if trying due to

• CA1304: Specify CultureInfo
• CA1307: Specify StringComparison
• CA1308: Normalize strings to uppercase
• CA1309: Use ordinal StringComparison