Create .NET RPC sample that doesn't use codegen

[timtay-microsoft]

I'm not sure if we actually need this, but it sounds like it may be helpful to confirm any feedback we receive from @koepalex

[koepalex]

Can we please just add the Utf8JsonSerializer into the SDK?

[timtay-microsoft]

I'd rather not. This library's core is not about serialization. If we pin ourselves to any particular serialization package (even System.Text.Json) we open ourselves up to inevitable security issues from that library.

[timtay-microsoft]

We've already gone through security reviews for this library where we were explicitly told that this is the correct way to handle serialization libraries. Changing course now may require another round of security reviews.

[koepalex]

As the code generation, would create this class I don't see the point, in the end tooling from us would cause this dependency in the application of the customer. Also, System.Text.Json is part of dotnet framework and no separate nuget anymore and used in other places also.

[koepalex]

Let's use this as real customer example and use the nugets instead of the project reference

[timtay-microsoft]

I'm not sure that matters for this exercise, but sure, I can do that.

[koepalex]

@timtay-microsoft is there already an example on how to use TelemetryReceiver without code gen in the repository? If not would you be so kind to add it?