Domain-specific content API call returns raw response

Computer Vision

## API Name (Kind)
`ComputerVision`

## Issue Description
The `AnalyzeImageByDomainAsync()` function returns a `DomainModelResults.Results`, but it is raw JSON response, meaning the user does not know what it can get from this response, until they print the whole response as a JSON dump.

The other API calls do not have this, they have properties that represent the keys.
Requesting a fix so the user is not confused and this function is consistent with the other API calls.

Suggestion: return the properties of the results similar to the following examples:

`results.Result.name` - the name of the landmark or celebrity
`results.Result.confidence` - confidence of the correct name or face rectangle
`results.Result.faceRectangle.width` - gets the dimensions of the found face of a celebrity

https://docs.microsoft.com/en-us/dotnet/api/microsoft.azure.cognitiveservices.vision.computervision.computervisionclientextensions.analyzeimagebydomainasync?view=azure-dotnet#Microsoft_Azure_CognitiveServices_Vision_ComputerVision_ComputerVisionClientExtensions_AnalyzeImageByDomainAsync_Microsoft_Azure_CognitiveServices_Vision_ComputerVision_IComputerVisionClient_System_String_System_String_System_String_System_Threading_CancellationToken_