Allow BannedApiAnalyzer to ignore GeneratedCodeAttribute

[dnv-kimbell]

Currently the BannedApiAnalyzer processes generated code that the developer has little control over.
It would be very helpful if the analyzer could optionally ignore code marked with GeneratedCodeAttribute.

The analysis framework seems to have some functionality in place to ignore generated code.
https://learn.microsoft.com/en-us/dotnet/api/microsoft.codeanalysis.diagnostics.generatedcodeanalysisflags?view=roslyn-dotnet-4.9.0

[bradwilson]

roslyn-analyzers/src/Microsoft.CodeAnalysis.BannedApiAnalyzers/Core/SymbolIsBannedAnalyzerBase.cs

Line 38 in 5ed3367

context.ConfigureGeneratedCodeAnalysis(GeneratedCodeAnalysisFlags.Analyze | GeneratedCodeAnalysisFlags.ReportDiagnostics);

[bradwilson]

An alternative here would be to ignore entry points. The code that's being triggered is a non-async Main method using .GetAwaiter().GetResult(), which is exactly what the compiler does when translating an async Main to generate the required non-async Main.

We are also willing to add GeneratedCodeAttribute to the class in question if that helps.