Enable use ASP.NET Core without MVC

We have hosting scenarios (e.g. Service Fabric) in which we'd like to use an ASP.NET Core pipeline but have no particular use for MVC. Currently, the ASP.NET Core support in Menes presumes you are using MVC—HttpRequestExtensions.HandleRequestAsync returns an IActionResult.

IActionResult implies the existence of an action, which in turn implies the existence of a controller. For this reason, the IActionResult processing in MVC can't be used in isolation—you effectively need there to be a controller.

Nothing in Menes needs this, so it would be useful to be able to plumb Menes directly into an ASP.NET Core pipeline that doesn't use MVC.

There is logic that would be required in any ASP.NET Core-based hosting that's currently buried in MVC-specific types, such as this code in OpenApiActionResult:

Menes/Solutions/Menes.Hosting.AspNetCore/Menes/Internal/OpenApiActionResult.cs

Lines 133 to 141 in d222fc2

    
           this.operation.Responses.TryGetResponseForStatusCode(this.openApiResult.StatusCode, out OpenApiResponse response); 
        
           HttpResponse httpResponse = context.HttpContext.Response; 
        
           httpResponse.StatusCode = this.openApiResult.StatusCode; 
        
           this.BuildHeaders(httpResponse, response); 
        
           Task task = this.WriteBodyAsync(httpResponse, response);

We would need to refactor this out into common code that can be used either from the IActionResult-based mechanism, or from something that plumbs in directly at the pipeline level.

Closed by #205

	this.operation.Responses.TryGetResponseForStatusCode(this.openApiResult.StatusCode, out OpenApiResponse response);

	HttpResponse httpResponse = context.HttpContext.Response;

	httpResponse.StatusCode = this.openApiResult.StatusCode;

	this.BuildHeaders(httpResponse, response);

	Task task = this.WriteBodyAsync(httpResponse, response);