Differentiate features in vcpkg

[daniele77]

It looks like using Asio standalone instead of boost/asio has been mentioned but not conversed about; that would be a drop-in replacement for all the networking features from what I was able to see in the code. Asio has a TINY compile time compared to full boost.

Another option for vcpkg users is to segment the remote cli features into a module, so you could vcpkg install cli or cli[with_remote].

Originally posted by @connorjak in https://github.com/daniele77/cli/issues/41#issuecomment-703419813