Check Web APIs returning ActionResult with status code 2xx

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Describe the problem you are trying to solve

ActionResult accepts a generic parameter but doesn't enforce strict-typing (related issue). But as what we have discussed here, it is ideal to improve the Analyzers instead of making the changes with the ControllerBase.

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Describe suggestions on how to achieve the rule

I am literally new with Analyzers (like a few hours ago) but it would be awesome if we will be able to check the MethodDeclarationSyntax of a ReturnStatementSyntax to see if the content type of the returned OkObjectResult matches the identified generic parameter from the method itself (please do correct me if I'm wrong on what I have initially thought for the solution).

I suggest displaying red curly underlines to notify the developer of the mismatch.

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Additional context

Even though I literally haven't tried making a single rule, I did a few moments ago but failed miserably (link to the repo - actual rule). Hence, went here to seek help.

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