fix: Skip properties that have no getter method during scanning

[y1hao]

Fixes #2980.

When a property that's used as ParamSource has no getter method (a write-only property), BenchmarkConverter.GetValidValuesForParamsSource() throws NullReferenceException. This PR makes it skip such write-only property since they can't be used as the param source, this will result in an InvalidBenchmarkDeclarationException which is clearer.

[y1hao]

@dotnet-policy-service agree

[timcassell]

Can you also add an analyzer rule for it?

[y1hao]

Sure. I haven't written analyzer rules before though, will take a look this weekend.

[y1hao]

Hi @timcassell, I just added the analyzer to capture this scenario. Sorry it took a bit of time.

[timcassell]

Can you also add the new rule to the AnalyzerReleases.Unshipped.md file? See AnalyzerReleases.Shipped.md for the format (don't include the version).

[y1hao]

Can you also add the new rule to the AnalyzerReleases.Unshipped.md file? See AnalyzerReleases.Shipped.md for the format (don't include the version).

Done. btw, I checked the failures in CI - that's our new analyzer rule catching our new unit test code for that scenario. I'm not sure what needs to be done for these errors?

[timcassell]

Done. btw, I checked the failures in CI - that's our new analyzer rule catching our new unit test code for that scenario. I'm not sure what needs to be done for these errors?

Suppress it in source (#pragma warning disable).

[timcassell]

Thanks @y1hao