Change to find current muxer (#11405)
Change to find current muxer (#11405)

Why we essentially move back to the original implementation in https://github.com/dotnet/cli/issues/2489 ?

It is more relate to the usage of corehost [CoreHost.cs](https://github.com/dotnet/cli/blob/342cf7949037a17f4bf18a59faf6fcff6a4d25b1/src/Microsoft.DotNet.Cli.Utils/CoreHost.cs)

Muxer share the same logic with Muxer.GetDataFromAppDomain, by the time majority of the logic of [Publish](https://github.com/dotnet/cli/blob/342cf7949037a17f4bf18a59faf6fcff6a4d25b1/src/dotnet/commands/dotnet-publish/PublishCommand.cs) is in CLI and it need corehost to find correct asset location.

As part of the work. It changed to the current way of finding FX location. But I believe it was a mistake to assume dotnet.exe will be in the parent directory (we did not count multi level loop up in). Since there is no more corehost.cs and publish is in SDK. We should use the simple and correct solution.

TryResolverMuxerFromPath is used when it was a separate library. And self contain app can get result from it. But it is also no longer needed.
livarcocc/cli-1,johnbeisner/cli,livarcocc/cli-1,livarcocc/cli-1,johnbeisner/cli,johnbeisner/cli