Copy endpoint info, runtime info, commmand parsing, and tests from dotnet/diagnostics

[jander-msft]

These changes move some source from the diagnostics repo to dotnet-monitor. This is done because the endpoint info (and related) classes are not used by the other diagnostic tools and allows dotnet-monitor to eventually refactor some of the abstracts into simpler forms. This change is the first step of just porting the code from diagnostics to dotnet-monitor without changing any of the functionality. Some of the test code was changed in order to fit the existing test expectations in this repository.

cc @josalem, @hoyosjs

[hoyosjs]

I am happy with this living here. However, does this affect in any way the triggers + channels functionality that was proposed? The ASP.NET Core library that was proposed at some point could live here with no issues.

[jander-msft]

I am happy with this living here. However, does this affect in any way the triggers + channels functionality that was proposed? The ASP.NET Core library that was proposed at some point could live here with no issues.

Chatted offline, but putting it here for everyone else. The pipeline implementations will remain in the diagnostics repo. The triggers feature will be partially implemented in the diagnostics repo (the pipeline and trigger conditions) and partially in dotnet-monitor (configuration of trigger conditions with actions and filters). The web API library will likely remain in the dotnet-monitor repo.