Make client for MTP and publish it as nuget

[nohwnd]

Summary

Provide package like vstest console translation layer, that will be able to recognize mtp processes, start them, send them requests and handle responses.

Background and Motivation

Orchestrating MTP is not super easy and requires implementation of the protocol which we documented but don't provide a public reference implementation for. If we had it then multiple places could take advantage of this client, for tasks like orchestrating runs, sharding (#4068), mutation runs and so on.

Proposed Feature

Extract the client code that we have in VS, and make it into a client package for MTP.

Alternative Designs

[Youssef1313]

Few notes:

• I prefer if we include JsonRpc as part of the package name. Just in case in future we wanted to expose the binary protocol used by dotnet test.
• We may want to address JsonRPC protocol epic issue #5490 first.

[Evangelink]

Also note that the rpc-json is quite slow and incomplete as compared to the pipe one implemented for dotnet test. This might be a better starting point for completness.

[nohwnd]

One more effort that would benefit from MTP having a client library on nuget: ionide/FsAutoComplete#1383